But I have to agree: Eventually, management will start to more aggressively monetize it (i.e., "pull the rug from under their free users").

Truly free (e.g., IRC) alternatives seem like the only long-term solution, otherwise people will keep stumbling from one commercial platform to another, because they never last.

they're requiring phone number validation just after registration or you run the risk that they suddenly lock your account, demanding a phone number for "abuse prevention". depending on ip reputation and possibly other factors it may be impossible to use it in the first place without providing a phone number.