There are tons of smaller XMPP or Matrix providers that didn't get access to millions in funding from these big corporations like Signal did. Who have to run a business in a way that requires paying customers from the start. But now that cash is tight (and after they built a sizable user base) and they can no longer just outspend the competition, suddenly they remind you of TANSTAAFL and are asking you to cough up the cash.
It is the same shitty playbook used by VC-funded companies, except that is now dressed as some virtuous thing of "looked at how much it cost to build all this..." It makes some emotional appeal but it tries to hide from the audience that these costs are solely due to them insisting on controlling everything.
If it is so expensive to run Signal, then open it up to let other people run their own servers instead of trying to control everything. Don't give me this bullshit of "we are a non-profit but we are in the same lane of big tech corporations". You are there because it served you. You can not have it both ways.
If you know of a good open architecture that solves the problems of spam and impersonation while maintaining the convenience and ease of use necessary for mass adoption, please share it.