I would also state that it is unfair to compare an app that doesn't have to worry about your privacy and solving real engineering problems vs basically making a web app that can easily sync your data because it's all stored on someone else's computer.
If that's the level of privacy you're setting you may as well use email for communicating. It's federated, it's easy to use, and everybody has one.
All that said, I do agree the Signal desktop app needs some work, but they'll get there eventually, and in the meantime I don't have to wonder if any of my data will be leaked to anyone outside of my intended recipient.
Funny you say that because Signal is the one with a crappy Electron app which is definitely a deal breaker for me. I mean I lose E2E with Telegram but gain really well designed and featureful platform apps that are native and non-gimped desktop apps (and a functional linux client. Signal's Ubuntu client just crashed for me).
Meanwhile, the Telegram desktop client is at feature-parity with the phone app with both running entirely independently on as many devices as you want.