Why bother - isn't the return policy enough? I'm assuming they are optimistic on new returns being new, but they are liberal on the return end to compensate.
Online shopping requires returns. Removing that option significantly reduces trust and value.
I suspect the cost structure and consumer behavior has forced their hand to be more restrictive on retail (and perhaps they no longer care as much either).
Another behavior I started seeing a lot more of the past couple years was paid listings selling a product for 4-5x the normal price, mixed in with the organic results. The only purpose of those is to rip off people who are in a hurry or confused and miss that they are being taken advantage of. They must work often enough to pay for the ad placements and clearly Amazon doesn't have any interest in protecting their customers.