Why? I don't need 10x more stuff. I'd far rather spend 10x less time working. If we're talking about an actual productivity increase, let's just produce the same amount of stuff in 10x less time.
It's a free market - if you can find someone willing to hire you to work 0.5 days a week, and are happy receiving the same income you do today, you can do so.
But your living standards won't improve, while everyone else's will, and by 10x.
And the people you are competing with to buy housing, a car, consumer goods, healthcare, food, and everything else - people who want to work 5 days a week - will have 10x more money than you. Resources like housing, which are supply constrained, will seem to go up dramatically in price relative to your income, and you'll be living in a slum.
Does that still sound like a good idea?
That sounds like a problem with that system. If we're 10x more productive why can't we make 10x as much nice housing?
Because the supply of land is relatively inelastic (and to some extent building materials and construction labor). There isn't suddenly 10x more land on the planet because we all start using AI. Maybe we can make more land or build taller buildings, but it gets progressively more difficult and expensive. And because of NIMBY of course.
And let's say that work is correlated with quality. Company A wants to spend 10x less time working, while Company B works 10x more. Company B therefore has a better product than Company A, so eventually Company A goes away. The consumer still consumed the same amount, but they switched to the better product.
Either the product was 10x better, which I don't think I need, or it wasn't really a 10x increase in productivity.
If everyone had said this 100 years ago we wouldn't have the Polio vaccine, air conditioning etc.
There are lots of problems in the world and there are still a ton of incentives to fix those problems. Yes there is also greed, scams, and exploitation - but that's never going to go away
If we got a 4-hour work week that might be a worthwhile trade.