> Most merchants don’t, and won’t, which is why regulators step in on the customers’ behalf
You're implying that regulators just show up out of nowhere and make tasteful decisions for a market. That's not at all how it typically works, and you should look into the history of the "lemon law" you reference. Customers have remedies of their own that don't require regulation or monopolies to exist.
> Costco, Amazon, Apple, some others, step in on the consumers’ behalf, which creates (as comments you are replying to) consumer loyalty and a kind of “brand halo” of consumer trust that the merchants all benefit from.
Costco is membership based. People have lost their memberships for gaming the return system. Amazon just passes the costs on. And Apple mostly manufactures their own devices. And, I can guarantee you, every single one of them has been sued by their customers at some point because of one of their practices.
Arguing that monopoly power is the "secret sauce" to achieving this is absurd.
> To say the marketplace platform shouldn’t be allowed to empower customers at the expense of sellers
The purpose of a marketplace is to create beneficial arrangements for everyone involved. Amazon interferes in this arrangement and then tilts it solely in their favor at the expense of both the customer and the seller.
> is to say markets shouldn’t be allowed to decide how much service customers can have and how much profits merchants are willing to forgo to be where customers want.
Markets should do this. A single monopoly player controlling a market shouldn't. You're splitting the argument right at it's fundamental point.