I'm ESL myself, and I sympathize because I also don't find it easy always to communicate with ESL people from yet other native languages. But as for the niche optimization problem, don't you think that the Amazon folks would say: this candidate was not able to think on their feet and think outside of the box, when given a non-standard problem? I think hiring teams over-estimate how far they can push the envelope on that in an interview, but I find it a bit one-sided to assume that the question was outside of the job they were hiring for or that it was a malicious question.

I’m not ESL but I still can’t communicate with people that have very very thick accents.

I’m sure they have a lot of rationalizations and just default inertia around various practices. Could the interviewer successfully answer a niche question proposed by the interviewee? If they can’t, should they forfeit their job to the person they’re interviewing?