Like fifteen years ago I would buy physical books, I still have a huge collection. I was getting really into math and would buy textbooks. Sometimes they could be pricey, but for a good hardcover, it can really be worth it if you’re coming back to it a lot.
Very early 2010s the amazon books became awful overnight. You could pay $70 for a hardcover and the damn thing would start falling apart a few days into reading it. I really don’t think I’m hard on my books, I treat them with care. These things just couldn’t handle normal wear for even a short amount of time. Paperbacks were even less reliable and only slightly less expensive. So I completely ditched amazon and started ordering books directly from the publishers. Normally they’d be like $10-15 more than on amazon, but it’s worth it, they weren’t falling apart.
Probably around 2012 I finished reading volume 2 of Francis Borceux’s “Handbook of Categorical Algebra”. Those first two volumes are genuinely some of the best math books I’ve ever gone through, it took me like a year each though. Volume 3 was very expensive to get from the publisher, I think it was over $160, but since I had gotten so much mileage out of the first two I decided I wanted to just pony up. It was clear as soon as it arrived that it was a piece of shit, and did start falling apart immediately. I left emails and phone calls and they just ghosted me and I couldn’t figure out a way to get my money back. That was the last book I bought for like a full decade, and I don’t think I’ve made a book purchase from anywhere over $15 since.
Pretty sure that was Cambridge University Press, and I had purchased something else (although much much cheaper) from them the year before that was good quality.
I still greatly prefer having a physical copy, but I pirate almost everything I can’t find in a library now.