Signal's architecture is completely centralized, by design. Signal explicitly discourages federation, which would allow distribution of the load over multiple providers. Session and Matrix work this way.
Even better would be a p2p app, which didn't rely on a central server at all. DarkIRC, Quiet, and Briar work this way.
Quiet team has a nice summary of most of the P2P alternatives in their FAQ:
https://github.com/TryQuiet/quiet/wiki/Quiet-FAQ
Even better would be a p2p app, which didn't rely on a central server at all. DarkIRC, Quiet, and Briar work this way.
Quiet team has a nice summary of most of the P2P alternatives in their FAQ:
https://github.com/TryQuiet/quiet/wiki/Quiet-FAQ