Why? You also need a driving license to drive a car. There are a lot of problems in this world that have a certain internal complexity. You can't UX it away. And the command line is exactly that. It's actually not complex at all. It's so simple that a student can write one before graduating from college. And the learning you need to do to use it is actually learning to interact with a computer.
It's really harmful that people nowadays act like hard stuff wouldn't exist and having to interact with hard things would be discrimination. Hard stuff does exist and you need to get used to handle it or suffer never to be able to do anything.
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Also email is actually one of the most simple communication protocols. It's so easy that you can manually read and write most of the stuff. You don't need anything fancy for it. A text editor is enough.
And while I think people don't need more than git and email or ssh, I'm all in favor of also implementing ActivityPub. One leg of stable distributed systems is the ability to use another transport if your preferred transport is not available.