For something more serious either buy directly from the brand, or from Costco, Target, Walmart, HomeDepot, BedBath&Beyond, BestBuy, Macy's, publisher's website, some specialized hardware, electronics or hobby shops. There is still a limited number of things where Amazon beats others, but their quality went down, and hassle free return is not hassle free anymore.
On top of that, they exhibit highly unethical behavior when it comes to counterfeit books. Here is a good thread by François Chollet about his book: https://twitter.com/fchollet/status/1550930876183166976. The main takeaway is this:
Q: What is Amazon doing about it?
A: Nothing. We've notified them multiple times, nothing happened. The fraudulent sellers have been in activity for years. The issue affects ~100% of Amazon sales of the book since March or April. That's because, amazingly, since fraudsters are claiming to have inventory, Amazon has stopped carrying its own inventory for the book (i.e. it has stopped ordering new copies from the publisher).
This is mind blowing to me, that they are still in the business of selling books.
And they did not really solve last mile delivery. Yeah, it is still faster, but I can wait for my sneakers for 5 days, instead of 2-3 and many retail chains can now delivery something to you in 3-5 biz days and can beat Amazon on return policy or warranty. It's odd that market forces aren't correcting this for Amazon.