But the interesting thing is that, statistically what they are serving maximizes their revenue. So they have the best version of what they want to do, and it keeps maximizing their objectives (profit).
The problem is that such objective became somewhat perpendicular to what some people like. It's funny but maybe watching that stupid Ad, somehow makes you do something that in the end makes them profit.
If I had to guess, niche products for niche interests have small ad budgets, but the random detergent ad buyer is happy to bid on anyone's eyeballs. You can't target ad buys that don't exist!
On the other hand, before I bought YT premium I was regularly getting ads for Chevron gas in Spanish (which I don't speak), and would be unsurprised if YT ad enshittification drove premium sales.