> I just want a damn API key, I keep it a secret and revoke if necessary and don't need 10000 layers of auth bullshit tangled up in every layer of every platform

Then implement that on your app... You are just generating a random key and storing a hash + salt.

Auth is hard only applies to auth for many users. For your own auth this is dead simple and made even simpler if you use a half decent framework...

If you are really worried about the implementation being insecure throw one of the many moderately frontier models at it, they are really not bad at finding issues in an auth system that simple.