Goodbye FLoC, hello Topics

I think the basic tradeoff is more like: you regularly visit a web site that needs to make $0.10 in revenue from you (to pay for operating costs plus profit), so they will choose to show however many ads for expensive electronics and fast cars are necessary before you'll spend an average of $1 on those products, or they'll show however many ads for diapers so you spend $1.

If you never buy diapers (but they don't know that), they'll have to show you an infinite number of diaper ads, probably with lots of provocative images and auto-playing videos to try really really hard to convince you to buy diapers which you don't need, and that still won't be enough. Whereas if they know your interests enough to show a single ad for something that is genuinely relevant and useful for you, you're reasonably likely to give them the revenue they need, and their site can be financially viable without an obnoxious quantity of ads. It doesn't seem surprising that many people would prefer the latter.