I think the big difference is that Google is free: everyone is using Google because it doesn’t cost anything and for a long time was the best search engine out there. I am sure that if Google would suddenly charge a few dollars per month for access, Bing market share would explode overnight, because it would become “good enough but cheaper”.

With the AI models, using a model that is “good enough but cheaper” is already an option.

I too am old. Google search is free, hard to replicate, and while there used to be lots of search engines, Google was (and arguably still is) miles ahead of all the others in terms of quality and performance.

A model is hard to train but it doesn't need to be hyper up to date / have a new version come out every day. Inference is cheap (it seems?) and quality is comparable. So it's unclear how expensive offerings could win over free alternatives.

I could be wrong of course. I don't have a crystal ball. I just don't think this is the same as Google.

Of course I could be entirely mistaken and there could emerge a single winner

In the first years, I remember no other search engine was close to Google quality. We all ditched AltaVista because Google was incredibly better. It would have been awful to switch back to any other options. We can already switch between the 3 big proprietary models without feeling too much differences, so it’s quite a different landscape.