Yahoo had 90%+ of the search market and they lost it in a few years to google because they were unable to innovate. I don't think anyone saw that coming. Everyone was building "portals" (remember those? AOL.com? I think verizon.com was one at some point with news and weather) to try and compete with Yahoo's dominance in search. It can happen again. LLM Chat is certainly an existential threat to the googs. Part of the OpenAI lore is that google originally viewed it as a threat to their search/advertising revenue model and defunded it on that basis.
The fact that people are willing to pay for LLM and use it over search seems to indicate that Google's free product isn't as good, and llm chat is better "Enough" that people are willing to pay for it.