They should be able to trust a service that promises security and anonymity for payment. In particular one that is touted as well renowned.

Especially since other groups can manage it properly, e.g. Signal can't link transactions to a specific user account

Should is doing too much work here. Its been doing too much work for our society as a whole. While I agree with your idealist sensibilities I regret to inform you that this needs to stop, you cannot trust institutions built on corporate profit seeking. Like that's just a hard no, it changes on a dime to seek profit somewhere else