What happens at 60% unemployment rate?

In the US, white-collar work has grown from 17.6% of total employment in 1900 to ~60% in 2002. Presumably, that share has grown even more and other first world countries have seen a similar trajectory.

Let's assume AI makes good on its promise to eliminate a significant fraction of these jobs (and doesn't go rogue). The remaining 40% of plumbers, chefs, electricians may not be replaceable for the foreseeable future, but they're not going to have a better time if a giant chunk of their customer base evaporates. Also, whatever tasks remain that only humans can complete; figuring out how to automate those is itself an intellectual task. At that point, AI can probably get to work on that.

I have no clue about the timeline. Let it be 1 year, 10 years, 100 years. Either way, what happens in the limit? When humans become fundamentally useless? What kind of economy is that? Is that a boom or recession? Where does the output of all that insane productivity go if consumers have no purchasing power? Who's going to buy Teslas and iPhones and shop on Amazon? Even advertisers and B2B companies are ultimately downstream of consumers. Why would I buy ad space from Google or Meta if no one can afford the thing I'm trying to sell? It seems the big tech end game is to erase their own market.

Everyone is saying we need UBI to prevent a social calamity. Never mind that, I think without UBI the market economy completely stops making sense.

I'm not particularly optimistic that UBI is going to happen. Governments are slow and the financial burden is high. Even if it happens, recipients have zero negotiating leverage to maintain it long term.

Are we doomed to descend into autocracy? I think that also doesn't make sense. Autocracies extract value from the many to benefit the few. But what's the point if there is no value to extract? Might as well be the dictator of an ant colony.

Is everyone just going to starve except a handful of super rich hiding in their luxury bunkers? That would be such an absurd outcome, given that we can feed everyone right now without AGI (kind of).

So what the hell is going to happen? I have no answers. But I don't even see anyone really asking the question.