I understand why they do it, and I have no problem with that. My problem is their lack of an alternative. Either have an alternative way for me to verify, or a way for an admin to let me into their channel without verification.
what if that alternative was "worse" than the phone number method? Would you then complain that there's no "easier" alternative?
For example, a photo-id as an alternative, which imho is way worse?
The problem with presenting an alternative is that if it is "better/easier" than phone number, then it gets exploited by the spam bots. If it's worse than the existing phone number method, then you'd have the exact same complaints, or worse.