I think people who rally against Amazon in this topic assume that the "savings" from much open price competition immediately come back to the consumer or the manufacturer. In my experience, with previous such tech improvement such as 'uber disrupting taxies', this has never been the case.

Both the consumer and the manufacturer/labor/driver/gig-worker always get the short end of the stick.... once AI-agents becomes indispensable part of life.

I would be surprised if you had enough data to be able to conclude such a lofty claim, especially accounting for increased availability of taxis in areas where there were none or few.

Either way, the benefits of price transparency are not imaginary, but they are also not the only factor. Things like insufficient buyers or sellers, government policy, etc are also in play.

All else being equal, a buyer being able to easily see seller A is more expensive than seller B for the same goods will result in lower prices for the buyer. But all else is rarely equal.