You could make an argument that Facebook doesn't really sort or categorise products by their properties, but eBay definitely does. You could also make an argument that Facebook isn't a middle man in the transaction because payment doesn't go through Facebook (unless you pick a payment option that does, of course).
I think you can defend Facebook Marketplace, but not eBay. When I use eBay, I don't wire money to John Stevens, I pay eBay directly.
eBay wants a cut, that means eBay gets part of the responsibilities too. Not for everything, of course, and they can always hold the seller accountable when those responsibilities become a problem.
