The reason I buy on Amazon is that finding anything you wouldn't see in a typical department store from somewhere else online takes a bit of effort; and it's an additional effort to gain some confidence that the "somewhere else" won't scam me, sign me up for even more spam, etc.

If there were some reliable meta-shopping site that aggregated trustworthy vendors, I would use that--but I can't see how to build one that wouldn't have all the problems of Amazon in the best case; and all the problems of wish.com in the more likely case.