No it's not. It makes no sense to say "oh, you can't commute to work and then home again five times a week? so how do you get groceries?" because those are two completely separate things in completely separate environments.
It's none of Amazon's business how people manage their disabilities outside of work. The only thing that matters is what the most effective way of managing their disabilities is inside of work. Amazon is not your doctor, and if your doctor says that this is the most effective way for you to manage things while being productive then they need to accept that the doctor knows what they're doing.
Part of which is that people face lots of stigma around disabilities still, but also the need to have some historical and diagnoses paperwork is a barrier that I suspect lots of people don't want to go through.
Frankly, I don't believe its rampant to begin with, and I can't find any real evidence that supports that people are widely abusing these accommodation requests.
Of course, this screws over people with problems who could get such paperwork before but didn't need to, as well as people who existed in the gap where they didn't need that before so now if they try to report it, they're going to get questions about "why don't you have a paper trail of this?", as well as "you didn't seem sick".
Because, shockingly, if you tell people, directly or indirectly, that you prefer the people who don't have an illness, they will learn to cover it up real well, or they get fired or quit when everyone but them gets promoted.
I have mountains of paperwork I submit at this point, because over time I have noticed a simple 1 page medical explanation was starting to get rejected, so I'd have to go back and forth getting more and more. Now I'm at the point where I am submitting 25 pieces of discrete information, from multiple professionals.
Frankly, it feels humiliating but I would negatively affect my life I didn't go through the rigamarole. Then there's the whole 'is this influencing whether I get promoted or not' questions and such.
When WFH became common place, it became so much easier for me to exist as a human being with some dignity left on the table, but alas, who cares about that, god forbid we give that any credence in the modern work place.
There's already a huge body of work about how people with disability face discrimination in multiple aspects of our lives, including work, yet the culture still thinks people want to declare these with HR because it makes their life easier? Oh it sure doesn't.
People who have never had significant physical impediments can't imagine "just push through it" being a thing that you're doing constantly so pushing further is going to fuck you up for a week or two, and so on.