It seems like everyone is trying to drag me to their favorite messenger
Yes, because people treat messenger choices as a popularity competition.
Look how many people I got to switch to crapware just because they wanted to chat with me! I must be super socially powerful! Woo hoo! Meanwhile, the technical consequences of this strategy are... predictable: crapware.
Opt out of all the noise and just stick to IRC.
Everybody reading this message should also read this, since it gives the details: https://github.com/haveno-dex/haveno/blob/master/docs/deployment-guide.md#register-keypairs-with-privileges
There are no servers in Haveno. Instead, there is a "developer (public) key" hardwired into the client. Instead of the owner of the localmonero.co domain (and TLS certificate, and onion url key), there is the "developer public key". The developer public key you have in your client basically decides "whose Haveno" you want to use. This is a good thing! I always worried about the localmonero.co domain being seized by a simple letter being sent to their registrar. With the developer key system this can't happen. The thugs have to actually go hunt down whoever has this key. The key isn't even kept online (like a TLS key or an onion key).
Whoever has the developer key decides who the arbitrators are. Just like localmonero -- whoever owned the domain name got to decide who the arbitrators were.
I think OP's posting is kind of an unnecessarily-scary way of saying that the client ought to ask the user to type in this key (or several of them!) at installation time, instead of being compiled in. That is a great idea.
If they were backward-compatible (with their predecessors) and interoperable, I would agree. But they absolutely aren't. The lack of backward compatibility in the chat/messenger space is abhorrent.