So the person that wants to sell that ultra-unique item that isn't produced by mega-corp, and the person that wants to buy that ultra-unique item despite unfavorable return policies never gets their needs met.

Why would that be the case? Maybe you’re thinking of customised or commissioned items, which are an exception explicitly called out in the law and require a defect by the seller to return (so you can’t just return eg a painting made for you on a whim, but if it arrives damaged, you can)