The main problem with XMPP (well for me anyway) is that the implementation of OMEMO that 99% of the apps use is woefully out of date, and Conversations (and their ilk) seem to actively resist updating because unless EVERYONE does it at the same time it will break interoperability.

The second problem for me is the ease of use, I'd have to physically set up accts for literally all my contacts on Jabber (everyone I know is stupid [it's really just learned helplessness and it pisses me off to no end]), but on Delta I can legit say "here, click link" and it'll bring up their app store on DC, then they DL and make an acct and then I say "click the link again" and they're directly connected to me, done. So much easier. And then next time I see them I can say "hey give me your phone I'm gonna do stuff to your Delta acct" and I can add relays and create a backup for them, but at least we can get started easier.

Besides, they are working on forward secrecy afaik, and they're one of the only teams making these apps that seems to acknowledge metadata's existence, honestly they seem like one of the best options all things considered. Sure if your threat model is the US gov then maybe not, but better not use Intel or AMD or any android (incl Graphene, and I'm a user myself) or iphone then. Carrier pigeons maybe.

Change has to start somewhere

I'm trying, but nobody has messaged me yet (see my profile, I've had it there for a while!) On the bright side, I guess I've enjoyed a lack of spam or other nonsense through sheer obscurity.

For someone just wanting a group chat with friends/family that they don’t want being used for AI training or sold to ad companies to build a profile on them? Deltachat is more than secure enough, and certainly better than the corporate owned options they likely already use.

Maybe, although I would argue that if the server is a concern already (E2EE makes it one!) then forward secrecy would be necessary to prevent a single key from leaking the group chat in question. And toward secrecy is no longer a new technology thanks to Signal.

I'm hanging onto DeltaChat with the hope they implement it as soon as PGP does.

I haven’t needed to authenticate anything manually in my experience in the XMPP apps I’ve used. I just enable OMEMO encryption...

I'm unfamiliar with the current state of the ecosystem, but... That's kind of the problem with it too, right? There is no standard, and unlike even Lemmy, the mishmash leads to user-unfriendliness. Specifically I was thinking of this comment , which may not be relevant to your client:

Group chats do not have group key, but one encrypt messages for each group member (pairwise), which means that everybody has to do key exchange with everybody. This does not scale... which means that even if membership is stable, new keys may appear. Some clients (Conversations) do not allow to send message to a group when they do not know some keys of some group members/devices , which is fail situation that happen pretty often.

Regarding attracting users, somebody else noted

If you tell people "on Android you should use this app, on iOS use that app" - you lose regular people fast. If you have a feature that only exists in one app on one platform, you also really lose people.

I definitely don't want XMPP to fail, but it seems that after years, it's all too little too late. That one, I'm not holding my breath on. (DeltaChat, I am.)

Or the server(s), no? It's trivially easy to archive, filter by account, and then decrypt if the one key has been found