Even its E2EE scheme is an oddball non-audited homemade one instead of an audited standard one like in Matrix for example. Telegram is fine as a Twitter alternative but I sure as hell would never rely on it for secure messaging.
Moxie exists because he helps centralize metadata collection on users looking for e2e encryption. All CIA has to do is pop the server when a fresh zero day vuln is found and collect. Signal protocol can be "secure" and still a useful asset to intellegence.