The Signal Server repository hasn’t been updated since April 2020. There are a bunch of links about this here but I found this thread the most interesting.
To me, this is unforgivable behaviour. Signal always positioned themselves as “open source”, and the Server itself is under the best license for server software (AGPLv3 – which raises questions about the legality of this situation).
Signal’s whole approach to open source has constantly been underwhelming to say the least. Their budget-Apple attitude (secrecy, i.e. “we can never engage the community directly”, “we will never merge/accept PRs”, etc) has lead to its logical conclusion here, I guess. I have been somewhat of a “Signal apologist” thus far (I almost always defend them & I think a lot of criticism they get it very unfair) but yeah I’m over Signal now.
The situation on iOS for XMPP is uniquely bad (but actually Siskin and Monal are improving a lot lately). It simply is unfair to look at only one tiny and for most people irrelevant (and uniquely bad) platform and extrapolate from that. On all other platforms XMPP works great and most clients have e2ee enabled by default for 1:1 chats (where it makes the most sense).
As for the other topic, sorry I didn’t want to sound so confrontational, but the same argument comes up all the time inside and outside of the XMPP ecosystem and I think it is simply false. There are other problems why XMPP isn’t adopted. Network adoption is driven by network effects. People invite other people to the network and when doing that they typically also recommend a client (& server). The case of a lone person looking for a new messaging system without any network is the rare exception and one that only comes up in the bubble where this discussion usually takes place.