Ah, ignorance of basic economic science on Slashdot once again. If productivity (automation, 1 man can do the work of 4, etc.) created unemployment, we would be at 99% unemployment or so by now. Instead, unemployment has been mostly stable, on a historical scale. 10% is actually about the unemployment pre Civil War, IIRC. So why, even though the avg. worker is 20x as productive as we were 200 years ago (a guess, I'm too lazy to look up the actual figures, but suffice to say our productivity has gone up a LOT thanks to automation) are we are not working 20x less hours? we have lots of extra stuff and services. Obviously this extra productivity hasn't stolen jobs yet. No, the extra productivity didn't disappear, it went into more stuff ("higher standard of living", for economists)
I'm not joking. On the macro level, all of that excess productivity gets channeled into making extra "stuff" that people want to buy. If everyone were happy with a 1810 standard of living, there would be no one to buy this extra stuff, and there would be much less work (because that excess productivity is wasted). But since we like having a standard of living higher than that of the average 1810 worker, there is demand for extra stuff. That's where the extra productivity goes. So while it takes fewer people to harvest food/make industrial widgets than it did in 1810 thanks to machines, the people who would have been working on the farm in 1810 are instead hard at work making cars, computers, telephones, and providing services that weren't cheap/widely available in 1810 like modern medicine, tour guides, or yoga training.
But ok, you want to take this extra productivity gain and translate it into more free time, not more stuff. It is still possible to do this, if you can find the right part-time job. Let's say you work for $10/hr for 20 hours a week, that's a half work-week.. That's $800/month. If you're willing to downsize to a 1810's lifestyle, it's very possible to live on $800/month. (For the purposes of this discussion we're ignoring gov't assistance). No telephone, no electricity, smaller house (a shack in the woods is nice), cheaper food (McD's probably more cost-efficient calorie- and protein-wise than an 1810 meal - meat was EXPENSIVE back then because they were more valuable as farm animals). Of course if you have medical bills you are sunk, but they didn't have modern medicine in the 1810's either. You can do this because you live in a high-productivity economy, and you have chosen to trade that extra productivity for free time, not for higher standard of living. As it happens, most people like a modern standard of living, and enjoying the benefits of modern science, so they work a full work-week instead.
On a national level, we can see a similar pattern in other countries. Underdeveloped countries still have low productivity and low levels of automation. People in these countries work full hours and have a low standard of living - they're basically 100 yrs behind us. There are some socialist developed countries that have, on a national level, decided to trade productivity for more free time, not more stuff. So the French worker gets 3 months of vacation a year, but has less stuff than the average American worker - smaller car, smaller house, smaller TV, less stuff (this is reflected in consumption statistics), less food (probably a good thing all in all). America didn't go that route, because we're not lazy like the French. Also, we kind of like being the biggest kid on the block, and that means work. But if YOU want that kind of lifestyle, if you make the right kind of decisions/are smart with career planning it is possible to downsize your life and trade excess productivity for time. Instead of devoting your education/work life to climbing the career ladder, devote it to engineering an exit into a decently compensated part-time, contract, or freelance position. Then reap the benefits of extra time. No robot butler yet, though, sorry. Of course if you WANTED a robot butler, you'd have to work full-time to afford one. Because on a macro level, that's where your increased productivity compared to an 1810s worker is going - into the stuff and services we can have that they can't have.
TL;DR - extra productivity from machines/automation doesn't cause unemployment, and doesn't disappear. It goes into higher standard of living. If you are willing to accept a lower standard of living, you can convert that extra productivity into free time.