It also doesn't help that all the privacy-aware tools suck. I was using Signal, but it was sufficiently unreliable that I was now forced to sign up for WhatsAp

It also doesn't help that all the privacy-aware tools suck. I was using Signal, but it was sufficiently unreliable that I was now forced to sign up for WhatsApp because Signal was practically unusable. And usability-wise, WhatsApp is sadly miles better than anything else I've seen, especially Signal. Great call quality, automatically reconnects (with an audible hint that the connection is down) instead of silently dropping your call, at least appears to work more reliably than Signal where recently about half of my call attempts failed and message delivery is pretty much random. Also supports read receipts. I won't even get started about XMPP where clients act out in ways that would make any non-geeky person immediately stop using it. Even for the more privacy-aware people, there is a limit to the brokenness that a person can tolerate. It's great that other messengers provide more privacy, but all that's pretty useless if they fail at fulfilling their main task. And that's before the network effect you mentioned.