Managing relays is annoying. If you have too few, names and convos start disappearing. Too many and your client starts crashing every few minutes.
Discussion
Yes that is shitty, I think for the most part it's shit clients but there will always be a limit to relays and wss connections are very resource intensive.
Some clients try to use a central server to fetch the content for you, but then you're at the mercy of that one server.