Hm, is the forced price country dependent? Because I’ve actually bought or found several products via Amazon, that I later started buying for less on the seller’s private store. Germany.
I routinely see higher prices on German Amazon than on other stores to the point of seeing sellers for third-party products asking for almost twice of what an item would normally cost when bought directly from a seller who doesn't sell on Amazon. For example you can buy Starlink equipment on Amazon but it'll always cost a good 20% more (or more) than you'd pay when buying from Starlink directly.
I'm not sure if the forced price exists in Germany for first-party sellers but it might explain why there seems to be a cottage industry of third-party sellers selling overpriced goods on Amazon. That is of course in addition to the universal problem of a dozen brands with names lifted from a word generator selling the same dropshipped white label product out of a factory in China at vastly different price points to create the illusion of choice.