If Mr ans Ms Smith are jobless, just as the rest of your neighborhood they might a) have no need for somebody else moving their lawn and b) might also have no money to pay other people doing stuff they could do themselves.
It is far fetched to state there is or even will be enough work for everybody. Most jobs, if not all can be automated. And the threshold, where it is worth to do so is falling continuously. How many people are required in farming today, how many people are actually working in a factory today, how many accountants are needed today, how many people are needed to service a computer today? With self-checkout lines in supermarkets and replacing of people for computers even in fast food chains, where do you think this will end? Clearly most if not all blue collar work can be automated. Not all of those people will qualify for white collar work (otherwise they would do this work already, i guess). And actually not even white collar work might be safe in the long run, seeing the current rise of expert systems. So it comes down to: who owns the machines is getting money, the rest would have no income. And it's not far fetched to say, that only VERY few will be the owners of the machines, probably the people who are already rich today, or their children. In my view it is, and will be even more so, necessary to distribute wealth in society. It's not even about injustice. Just think about it: Who would buy stuff from the rich robot owners, if everybody has essentially no money at all?
Society and even capitalism live from wealth being spread.