I don't really mind seeing this cycle wind down, however it does raise a question that's existed even at the height of these centralized platforms...What the hell do we use to chat with individuals online? Discord might work okay in small groups, but it's still a single company-owned platform, so those free servers aren't going to last and you'll lose that space eventually. The only big name alternatives that come to mind for decent cross-platform carrier independent chat are either owned by Meta/Facebook (Messenger/WhatsApp), or are Snapchat or Telegram.
Meta's problems are obvious to those that follow tech.
Snapchat's in a weird limbo so far as I'm aware, where it's no longer as popular as it once was, as younger demographics I think are skewing to TikTok now, and I don't know that it ever really saw wider or consistent adoption outside of those demographics. Beyond that Snapchat is just another single company desperately trying to monetize their platform as much as the rest.
Telegram's probably the most viable competitor to WhatsApp if I'm not mistaken, but the head of it & group behind it are as questionable as Meta/Facebook, at least imo.
I guess the real alternatives might be to try to set up and host one's own IRC/XMPP/Matrix servers, but...That seems impractical for small group chats, no? Or maybe it's not as costly nor cumbersome to spin up & maintain as someone not too familiar with it might think? 🤷
Edit: As to email as another option for individual comms, uhh, well all I know is that's probably the one thing you'll frequently see many self-hosting folks recommend against trying to host yourself due to major email providers by & large blocking random small self-hosted email servers.
A small problem I see with Signal though is the phone number requirement. Maybe it's just me, but I'd rather not bind a chat app to a phone number...There's the privacy/security benefits, sure, but also some added clunkiness with a new device/number (particularly if the old device was broken or lost).
You can also use one of the many open servers or the main Matrix one. It doesn’t matter, it’s all encrypted and federated.
It kind of does matter though...Maybe not a ton to those just chatting in them, but if you're relying on someone else's hosting, it's only as good as long as it's hosted (and as good as its admins/mods). Part of the reason I'd be a little more interested in sorting out hosting for smaller scale chat stuff myself, as of the many things you could self-host, it's up there as one that makes more sense to me.
Also just checked out Delta.chat, and that's pretty sick! Thanks!
Signal has over 100M downloads on the Play Store for Android alone. I think it's well into the big names territory albeit at the lower end of the scale. As a non-profit, the Signal Foundation can probably hold the front for now as the go-to alternative to for-profit data farms.
It's an interesting one I've been keeping an eye on, for sure. Last I checked it was still lacking in terms of cross-platform support however, albeit with some work on a Windows build on the horizon.
It's understandably slow-going, given their aims of striving to ensure privacy & reliability even in the face of internet lockdowns.
Edit:
This made me check back in on it, and I'm glad I did! There's still no iOS version available, but they just released a macOS version which may help lead to further work for such a version!