That's a cynical way to look at it. Most likely the LLM will take a cut of sales and they'd be more or less indifferent who cuts the check. There's a market for this sort of thing. People will go to the best LLM for shopping. If the LLM is a shitty product, people will switch. LLMs are increasingly commoditized.

All you say is true for an aggregator like Amazon. But Amazon is better than Nike.com because as an aggregator they go from 1 to many retailers. LLMs will go from 1 aggregator (Amazon) to many so it will be better. And they don't have to invest a lot in UI/UX as chat is the interface.