Have you not encountered the eleventy billion subscription services and merch stores? Those make a loooooot more money for creators than ads these days. Even the dirt cheap ones. Similarly, there's a reason so many youtube channels get their own sponsors instead of relying on youtube's ads pittance.
If you successfully block adblock (tall order is tall), a lot of people really do just go do something else, instead of resigning to the ads firehose. And adblock users are still (somehow) in the minority, I think.
Also, this loops right back around too Google's ad monopoly. They have a stranglehold on both sides of the market, able to maximize spend from marketers and minimize payouts for those showing the ads, to maximize Google's profit at cost to everyone else.
Before theft-by-Gemini-Summary, there was Google News, with Google just wholesale copying articles into Google's feed reader so they could collect the ad revenue instead of the writers and publishers.
They've abdicated any right to complain about copyright violations of their own IP, at this point. Either copyright law is the law, or it isn't: can't be both ways. In practice, lawyers cost money and Google has much more than Random Adblock User 6, but morally speaking, they have no high ground to speak of.
Anyway... If Google doesn't any longer drive traffic to websites, then the operators of said websites will no longer have a reason to allow Google to index them in the first place. You can't have a very effective search engine if too many major sites block its crawlers.
I don't think the AI bubble is going to last, but if it did, I expect this all would end up compounding the "LLMs training on LLM generated content and churning up other LLM content" spiral into ever more useless drivel.