Companies don't serve poor people; they have no money. Companies will pivot to serving the people who have money. If that means they only serve rich people, then that means we'll have more yacht makers and fewer dollar stores.
More likely is people are stripped entirely of any economic value and influence. Tribesmen struggling to survive in a mad max apocalyptic scenario while the world's money is spent and made in a business to business environment, in protected sites defended by autonomous loitering munitions that the uneducated masses attribute to god entities within a few generations of knowledge loss.
Rich people are limited resources and they would not buy 100 yatches even if they could afford it. As seen in history if the majority of people in a country is poor, revolution is just a matter of time. It's in a countries best interest to make sure wealth at least somewhat evenly distributed. At least good enough so the masses won't get angry.
Right now they're going on ~5-10 superyachets each. I could see them buying 100 in the future after they're 100x as rich. I think 5-10 which are 100x larger would also count for these purposes.
For car collection people will keep going well into the hundreds. Hell Jay Leno just did a video with Joe Biden yet again and his corvette, but Jay Leno famously has hundreds of cars.
Hoarding wealth is itself quite boring. There are many goals a person could have for their life, and "getting more money" is the least interesting. My question is always, TO DO WHAT? If you can't answer that question in some way that helps people (and then follow through if/when you do get that money) then your life is hollow no matter how many billions you have.
Early industrialization meant industrial canneries to feed people, building cities to house everyone from the countryside, indoor plumbing.
And the AI revolution is no housing, worsening food, a few people with yachts, the Epstein class getting away with what they want to do, and no new plumbing hookups because the datacenter took the municipal water supply.