I...don't have this experience. It doesn't hold true for me, and I suspect I am not alone. There are certainly some online stores that are not very great, but by and large, I just don't have problems with them. I prefer the seller's website over Amazon.
Amazon, on the other hand, is plagued with fake or bad products from copycat sellers. I have no idea what I am going to get when I place an order. Frankly, I'm surprised when I get the actual thing I ordered.
it's still the case today, in 2025, that when I bought a Focusrite 18i20 mixer from Sweetwater that turned out to be defective, I had to spend a week with a lengthy and super-long-delayed conversation with their support department convincing them that the unit was in fact defective, that I was using it correctly, and finally getting the prized RMA to return it. Whereas if I had bought it from Amazon, I would have received the original package more quickly, and when defective, I could have had it in a box and shipped off from any local shipper that same day with no emails/phone calls required with a new one to arrive the next day. Amazon even as the leader in "enshittification" still offers a dramatically better experience for a wide range of products (though certainly not all of them).
A couple years back I tried to buy some parts on digikey and literally could not get the checkout to work without completely disabling noscript (assuming that would've helped). They had like a dozen 3rd party tracking scripts. Eventually I gave up and used Amazon.