Forget the elephants – there's a donkey in the room (pmail.com)

Google really is worse than other vendors when it comes to authentication.

Google is the 800 pound Gorilla, people are going to have to do whatever it takes to work with them.

I did a shootout of 8 image analysis APIs, I was able to get the other 7 working in under 20 minutes. Google took more than two hours because of it's overly complex authentication and trashed my Python installation when I installed the API client.

    it has also required me to write nearly 7,000 lines of code,
    just to support GMail —

    A full HTTP/HTTPS client for validation and token issue

Oauth2 is a bag of hurt, but FFS this is so hyperbolically exaggerated that it's nonsense.

If you had to "write a full HTTP/HTTPS client" just to talk to Google, that's on you for using tools without decent libraries in 2022...