Author here. I just updated the post with an additional idea for fixing the free tier, suggested by several readers.
It turns out there is a non-widely-known program called AWS Educate Starter Accounts [0], which give no-credit-card access to a limited but useful subset of AWS services. The problem is that you can only get access to these accounts through student affiliation with a participating educational institution like a high school or university.
It might be more feasible to expand this program, say to any applicant who demonstrates some reasonable threshold of non-bot-ness, than to re-engineer the normal free tier.
To any AWS people reading this: I believe this could be a useful step toward solving the free tier problem, and would be happy to be a sounding board.
[0] https://aws.amazon.com/education/awseducate/aws-educate-faqs...