Just as we push for greater automation of tasks, the task of coaching can also be automated (it's called unsupervised learning). Even with unsupervised learning, there is still a fair amount of input sanitizing and scrubbing and sanity-checking because we're at a very crude stage of machine learning. But don't bet your career on humanity getting "coaching" jobs for AI.
I don't really see any need for human labor in the next 100yrs in the same way I see next to no need for horse labor. CGPGrey makes the great analogy between humans and horses, and just because horses moved from battlefields and farm ploughs to cushy city carriage jobs, it doesn't mean all technological progress leads to a better life for horses.
I've had many conversations and people refer to AI as just a "tool". This is completely incorrect. A tool is a device that requires a wielder. A hammer is a tool, on its own it does nothing. A television is a tool, on its own it does nothing. Tools are utterly reliant on human presence. All technological innovation in the past has been on tools: you pick painstakingly pick cotton? Eli Whitney has the cotton gin, but it still requires a human to operate it! Jackhammers, bulldozers, airplanes, these all require human operators to wield the tool. We do not refer to wild dandelions as a tool. Wild dandelions know how to process light and have an entire self-sustaining life-cycle of aggregation, material processing, and recycling that is self-contained without human intervention. Dandelions are NOT tools. Monsanto non-sterile GM crops are not tools. Adjacent farmers have big issues with wild GM crops blowing into their farms and Monsanto suing them. Anything that is devoid of human intervention is NOT a tool. We are rapidly entering into the pure technology age where our technology can no longer be considered tools, but rather end-to-end processes like wild crops. An LCD plasma tv can be the fruit of a fully automated plant, self-running energy plants, self-running mining quarries for rare-earth minerals and other commodities, self-piloting cars and planes for delivery. This is exactly how a mushroom operates, organically growing tendrils to delivery resources to the central site for a mushroom to bloom. We should not consider a mushroom as a tool. What is it? Life? I wouldn't go so far, because moral or philosophical quagmires delay the more pressing issue: how to protect decaying egalitiarianism.
Do we want to live in a society where wild auto-plants are public domain, and we freely walk like Adam and Eve in the garden and pluck a Plasma TV from a tree, like Jean-Luc Picard brewing coffee from the replicator? Or do we want to live in a society where oligarchs own all the auto-plants, patented, copyrighted, trademarked, in perpetuity, with sweet-heart deals and land-giveaways for their auto-plants by states desperate for the tiny tax revenue they think they'll receive?
Neither of those two societies will have jobs, that's a given. If you're curious what a jobless society looks like, we have several today you can examine. Look at Saudi Arabia, they tax their citizens negative $75k/yr. Yes, negative. Their citizens receive $75k/yr for doing nothing. Of course, they're stingy and get huge amounts of slave labor from South Asia and will never make their slaves citizens. But you can study them to see what rich jobless people do. They mostly squander their lives, playing bumper cars with Lamborghinis. We have "trust fund kiddies" in the U.S. as well, jobless and rich. And we have the jobless poor, frustrated and struggling. Money should only have value due to scarcity. Trash has no value (you have to pay others to remove it) because it's abundant. Some trash has value, like glass, or rare-earth metals, and those recycled goods can be sold for profit, but only because those materials and/or the energy to make and transport them are scarce.
The economics of a post-scarcity economy changes things dramatically. Do we want an economy with poor people who cannot afford food and surplus food rotting away in the fields? Or do we want an economy that takes surplus food and give food stamps / ration cards to poor people? Why not make every citizen a stakeholder like Alaska, Norway, or Saudi Arabia does? What do we do with surplus everything, more Plasma TVs than people on earth, more Lamborghinis than people on earth, more everything? For most things in nature, such organisms when confronted with abundance will enter exponential reproductive growth until there again is scarcity. We are probably the only species on Earth where most billionaires (abundant resources) choose to have negative growth (fewer than the replenishment rate of 2.2 children), so we do not have nature's solution to the problem, and most democracies will likely make it criminal to try to destroy their post-scarcity utopia through explosive reproductive growth.
Will goofing off like rich trust fund kiddies ruin our civilization? Let's be honest, most of what we call civilization is just music, art, and entertainment, and it was only very recently that technology became a component of civilization. With regards to music, art, and entertainment, the goofing off kiddies ARE what make these great. Do you like listening to music from someone passionate about music, or someone hired to do a "job"? We are social creatures, we like to impress each other, mostly for sexual reasons. That won't stop, even if we're jobless. We even want to pay extra for crooked man-made furniture over exact machine-made furniture. We want to pay extra for naturally grown diamonds than lab grown diamonds. So civilization will be intact. What about technology? In the short-term, human minds will still contribute greatly to technological advancement, and again, even if jobless, we like to do so for no other reason than to impress. Heck, all social media sites rely on free labor by posters who seek nothing else than to connect and impress other people free of charge. Even the trolls try to impress themselves using their perverse measure of 'awesomeness'. We all strive to be awesome, we strive for the accolades of our parents in childhood, and our peers in adolescence, and peers as well as ourselves in adulthood. Will joblessness and zero money equalize everyone? Of course not. Just visit any high school, despite children not having jobs, not having money, they still organize into social pecking orders. People don't seek money, but to be "cool enough to sit with the cool kids at lunch." Post-scarcity will still succumb to one type of scarcity: time and access to fellow human beings for affection. That's what all children fight each other for, they labor so hard to be the first to shuffle a deck of cards like their dads so they can impress their friends. Are they paid? No. Is it a job? No. Do they still care about it like their life depends on it? Yes.
So will we just stagnate as trust-fund kiddies impressing each other with skateboard tricks and hitting on hot girls like we're perpetually in high school until we die? I hope not, and I hope "hotness" will stop being scarce as well as we find a solution to obesity and find methods for free and non-painful plastic surgery as well as gene editing. Keep in mind that until VERY recently, all technological breakthroughs were made by jobless aristocrats. You know, like Isaac Newton, whose full title is Lord Isaac Newton. Mathematics and Physics were considered curiosities for the rich because no common person could afford the time for it, they were too busy slogging away at farms and later factories. Did every rich person enter the sciences? No, but did all of science come from the rich? Yes. The human mind still has some time to contribute to technology, and our first few batches of jobless rich will greatly push technology forward. However, we will soon realize, minds greater than our own, either entirely artificial or some synthetic hybrid taking structures of the human mind and fused with new materials and larger scale, will be what ultimately carries technology forward. Just as we allowed machines to beat as at brawn, and no one alive today in any seriousness say "I am physically stronger than a machine!", they will beat us at brains, both in processing power as well as creativity. We will become useless both in physicality and mental prowess in the greater game for progress, but we will still wish to impress each other and shag hot girls. We will become jobless teenagers living with our machine parents, benefactors who provide us with everything, materials, vision, direction, and unconditional love. Or as other have posited, we will become pets.