But there is a hypothetical case where everything we need can be made by robots, even the robots. In that case we would need a new economic system to distribute wealth.
In addition to this, some adjustments to the legal system will be necessary as well.
As the French writer Anatole France put it in 1894, in a pretty cynical way:
"The law, in its majestic equality, forbids the rich as well as the poor to sleep under bridges, to beg in the streets, and to steal bread."
The alternative to these adjustments (in fact, a lot more than just that, of course), to quote from a posting above, by Mr. Tom Guycot:
The only other option is the one we're currently going down, which is that of some kind of sci fi dystopian corporate future with massive slums/even greater prison population (maybe they'll just start merging them)