I think there is a lot of room in ecommerce for a "trusted brand" like costco where you can just thoughtlessly buy from because I trust they did the research.
Amazon used to be that around 2013/14, but now I prefer to spend more and buy things elsewhere because I don't have to do so much research to make sure the product doesn't suck.
I wouldn't even mind an affiliate-funded intermediary that just listed the top #5 things from WireCutter for a given category, + some picks from Consumer Reports.
(As long as they didn't link to Amazon, it's not safe to buy there.)
Ironically, brandless tried to be this for lower dollar items. But there is another story on HN right this second about brandless failing and shutting down.
Amazon used to be that around 2013/14, but now I prefer to spend more and buy things elsewhere because I don't have to do so much research to make sure the product doesn't suck.