Small outlets rely on distributors that rely on warehouse workers and pickers.
Just about everything people use, eat, ride, drive, or wear relies on warehouse workers.
Most non-Amazon warehouse workers are treated worse and paid less than Amazon employees.
If you hate Amazon so be it, but hating them for the way they treat their warehouse workers and pickers is not rational unless you hate just about every modern business equally.
You don't, though, which is the other person's point. Unless you've radically changed your consumption habits to only buy directly from producers (and ecommerce is ruled out, since you're not okay with the typical conditions of logistics employment). In reality, you've singled out Amazon. Which is fine! But at least admit that. It's a political statement, you haven't achieved labor rights veganism.
Off course, it is totally fine to participate in things and also criticise them, as that is how things improve. But if everyone obsess on a company not in the bottom of bad behaviour, this simply gives more power to companies behaving worse. One can off course claim that their criticism depends on the PR perception of the company,but I guess that's not fashionable.
I don't think the argument is everyone else does it. The argument is Amazon is paying much higher than many other companies for the same job, and still being focused over, while companies paying less get a free pass.
Edit: or maybe not.
Interesting concept when you consider how deep the supply chain is for all the raw materials. The provenance on lithium and silicon would be critical I'd think.
Obviously most businesses cannot realize fully automated picking yet, but even those who can't: preventing employees from drinking water is a human right violation.
And for the German market for example there is book delivery from thalia.de which can deliver via mail or to a book shop. (And momox.de for used book buy/sell - I stopped selling books on Amazon years ago because it's just too much effort, Momox has a simple bulk preparation)
I've worked in a couple warehouses and have a lot of friends and colleagues who have, too (I never worked for Amazon, but a lot of said friends and colleagues did). The consensus is that Amazon's treatment of its warehouse workers is about as bad as it gets. There are plenty of warehouses that take employee safety seriously, that pay well with decent benefits, that allow their employees to take restroom breaks instead of forcing them to resort to pissing in bottles at their pack stations (seriously, Amazon, what the hell?), that put at least some semblance into temperature control (as difficult as it may be to do in a large building like a warehouse) and that overall treat their employees like human beings instead of machines.
It's good to be skeptical of the treatment of workers as a rule, but there are definitely different circles of Fulfillment Hell, and working for Amazon's pretty damn close to the inner-most of those circles. Amazon does pay better than average, but there are apparently few companies that treat their workers worse (at least in the US).
But I mean when there is no other alternative, it would probably be exaggerated to not buy at Amazon in the current situation...
You also seem to be applying black-and-white thinking to problems of right and wrong. Some things are more wrong than others.
On a scale from "single mother cheating on her taxes so she can feed her kids" to "cold-blooded murder," Amazon is (in my opinion) beating puppies with sticks. When someone does something not just wrong, but inexcusable, and is unapologetic, I don't say to myself, "well, lots of other people have done/do bad things." I doubt you do either.
I did a lot of research about the 'picker industry' for that case. What a nightmare job. I can't imagine having to work somewhere like that with all the rules, quotas, bully leadership, favoritism, etc., worse than the Army.