Retailers do not want you to make better choices. They want you to buy the widget.
A lot of evidence suggests that also shoppers aren't that interested in making the best choice either. They want to make a tolerable choice with as little effort as possible. There is no basically no consumer market for "power shopping" outside of weird niches like pcpartpicker.com etc.
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.
Shoppers do not want to pay to shop. Retailers pay thousands to encourage you to shop with them. They are the economic buyers of this feature.
> for a lower price
Catalog is impartial, chatbot is ads pretending as advice.
Am I the only one that think Amazon has gotten pretty awful in the last 5 years?