I acknowledge that this isn't an option for everyone but for the HN crowd, it's fairly easy to run your own homeserver. You just need to install Synapse [0] (which has a convenient Docker image [1]) and give your server a domain name.
If you do this, your metadata will only be accessible to yourself and the homeservers of your contacts (who could share your server or run their own).
Message contents are usually e2e encrypted, so the homeserver you use is irrelevant.
And Linux, as well--including the Librem 5 phone[0].
>no media
The media attachments feature was in alpha nine months ago[1]. I guess they are still working on it.
[0]: https://nico.dorfbrunnen.eu/posts/2020/briar-alpha/.
[1]: https://code.briarproject.org/briar/briar/-/issues/1669.
I think the point is more that in e.g. the US, nearly half the population has an iPhone [1], so a chat service that is only available on Android and Linux can't spread as much.
[1]: https://www.counterpointresearch.com/us-market-smartphone-sh...
Oh, no, I was absolutely aware that he was referring to the Android-iPhone pairing, as in "it's Android-only as opposed to available on both Android and iOS, as every major messaging app"; I just wanted to specify that it is not only available on Android, but also on Linux (PC and phones--I guess you can use it on the Pinephone, too, besides the Librem 5).
[0] I don't think it's an efficient, non-distracting or just desirable means of communication.
[1] https://briar.app.