Well, once AI takes over most of the white collar jobs, people will have to do something to put food on the table, and not all of them can be gig workers. Or do you see ideas like Universal Basic Income as an alternative for the US?
I'll worry about the Deus Ex Machina when it's here. Until then, AI is mostly generating a lot of text and burning insane amounts of energy, and we have bigger problems to worry about. Like a president diverting ten billion dollars of tax payer money into his cosplay UN for crooks and dictators.
That's argument is a bit rough given manufacturing is one of the areas seeing the most automation progress and success. One of the main reason it's not more successful is labor costs can be lower than automation that wouldn't be true if we wanted to replace the income of white collar workers in the US.
If we end up in a place where AI and automation take over then yeah I think we start looking at alternative income sources and economic system. Just like star trek predicted we would do after WW3.