The days of search for untrusted sources were numbered even without LLMs. LLMs are simply accelerating the process. Why would Google simultaneously watch one of its core products fail and fail to invest in what is likely to replace it?

I don't really buy into this theory that they want to keep all of their users on their site due to advertising revenues. The effectiveness of search engines has been degraded for decades due to SEO, and it seems as though search engines have been having an increasingly difficult time managing it in recent years. AI on the backend may help them contain it, but it comes at considerable expense. While it may help them grow their market share, it won't help them grow the market and it is a market where people expect the service for free. On the flip side, companies are already starting to sell AI services, so it can generate revenue even before advertising is factored into the picture.