I agree that gpg did not age well. If we compare it to a different project with similar history: curl, it's apparent that gpg chose wrong on several fronts. It should be a library first instead of a cli tool. Funny part is that even the library of gpg (gpgme) is internally calling the binary.

I've played around with designing a higher level library to OpenPGP once (https://pypi.org/project/pysequoia/) and personally I think it yields more readable, faster and secure code.