I’m guessing, they did it this way, because there’s no persistent process to keep the decrypted files open. You’d need to ask the user for the password for every single command they run. With GPG, that persistent process is gpg-agent.

Of course, encryption with a GPG key is also going to be more secure than the longest password you can come up with.

I guess, many people will want access to GPG, too, if they want access to their passwords, so they’re not bothered by it.
But yeah, I do also remember setting that up on Android, where you need a separate app to do the GPG, and it really stops feeling simple pretty quickly…