Wire is not for people to leave message unread for 3 months. Most user can deal with that. And once it is read. You can archive your message on to a file (and then put on USB). For most users, why use anything else?

For those who like to leave your message unread on the server for up to a year, then go with signal or telegram.

In a flawed world that deals perfectly with its flaws, infinite storage would be a service you can optionally buy from an open market of third parties, alongside optional identity mediation (for those who definitely don't want their identity bound to a device or SIM or some other PID known to the core network). Bonus points if the technological and organizational interface between third party and core network is paid, I believe that this would be one of the least bad ways imaginable of funding the core network.

Yes? I want them to hold to my messages in am encrypted form for all time. The NSA has probably logged them anyways. I'm done with managing my own backups, my state should be persisted "in the cloud" with no effort from me.

I think it should be an option, at least.