It's your choice, of course, but in my opinion Electron is the only decent cross-platform UI framework. Without Electron there would be no Linux version.
Really? I joined a few groups but couldn't figure out how to post, and there was an emoji drawer eating up 1/3 of the screen, and was unable to be hidden. I consider myself a smart enough person to write an app that performs the role of Telegram, I shouldn't have trouble learning to use it.
Of course it depends on where your interests lie but here's some examples: VLC, Spotify (Linux), old Opera, Krita, Google Earth, Tesla Model S in-car UI, webOS, SailfishOS, AMD's Radeon Software Crimson driver tool, and many others including what's already mentioned, Battle.net.
Any Qt app can be themed with CSS (Qt calls it QSS) as if it was an HTML page, just like Electron apps can be. You can completely change the design, if you wish to.
So, in terms of design, there’s basically no major difference there.
it's not like there are hundreds of cross-platform win/mac/linux software that have no problem being written in other frameworks than electron. See all the KDE apps, Krita, Inkscape, GIMP, Wireshark, Audacity, Unity3d, Maya, Houdini, Blender, LibreOffice etc etc which are all hundreds of time more featureful that your average Electron app.
I'm not against electron app, in fact I think it's a really good idea. But saying it's the only good ui framework is disingenuous.