What’s changed is that they don’t care about packaging books anymore. Previously they would ship books inside of an airgap in a box, or at least inside of a tight box that would prevent damage. Now they will just throw it into a Mylar envelope that offers no protection against bending.

Agreed. Bubble envelopes can work okay if they are the correct size, but I often get normal-sized books shipped to me in XXXL size Amazon envelopes. These mailer envelopes are big enough for the book to rotate freely in amy direction inside of the packaging. So it’s inevitable that it arrives with creased or torn pages and jacket. I even had one where the cover separated from the pages. Horrible.

My preferred approach now is to use niche-retailers for things I care about arriving intact on the assumption that if your entire business is about that product category then you should be knowledgeable about how to ship those items safely. Barnes & Noble for books, B&H for camera, BestBuy for consumer electronics and video games, etc.

Yeah, Amazon loves those bubble bags and even just the mylar ones. They aren't careful enough about what sort of items go in them. Many items are fine that way but more than once I've gotten completely destroyed packaging around an intact item. Fine if I was simply going to use the item anyway, not so good if I was ordering it for someone else. I've also had a couple of cases where I was surprised it survived.

I suspect they are playing the odds, accepting that they will have to refund a few items that got smashed from inadequate protection.