It's not really designed to solve anything. It just exists. The cool thing about it is advertisements are not possible natively. There is also no JS. So no creepy ass trackers. It's basically like the very early days where JS or CSS was not a thing. Just markdown. With the additional security and privacy stuff of the modern web like encryption.
XMPP as a protocol was great. But the problems the servers had, the mess is just a no go.
SimpleX is far better in privacy and usability in my opinion. I doubt XMPP will recover anytime soon.
Discord has an alternative called Revolt that is open source. It has all the premium features in discord for free, but is still in early stages I'd say.
I like how much the design resembles YouTube's design. I would believe it if I didn't know about the state of mobile phones.