We actually can prevent it. We will go back to human-curated websites, and the links to those websites will also be maintained by humans.
This is how the early web used to work in the 90s and early 00s. We will see a resurgence of things like portals, directories (like the Mozilla Directory project — DMOZ), webrings, and last but not least actual journalism.
Unless Google manages to find a way to tell AI content from human they will become irrelevant overnight because Search is 90% of their revenue. This will kill other search engines too, but will also remove Google strangle-hold on browsers.
This also means we’ll finally get to use interesting technologies that Google currently suppresses by refusing to implement them, like micro-payments. MP are an alternative to ads that was proposed a long time ago but never allowed browser support.
MP are a way to pay very small sums (a cent or a fraction of a cent) when you visit a webpage, and to make it as painless as possible for both the visitor and the website. It adds up to the same earnings for websites but introduces human oversight (you decide if the page you want to visit is worth that fraction of a cent) and most importantly gets rid of the ad plague.