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

I would say Google's monopoly mainly comes from its name recognition, definitely not because its still ahead in core search as I have been using DuckDuckGo for 2 years once I noticed search results are the same or better than Google.