None of the popular/successful apps are bad.

They usually have great ui/ux and are being actively developed or at least maintained. Think google maps, apple wallet, or of course discord. What is hot garbage, however, is having to accept massive privacy violations if you use them. Vencord unfortunately does not mitigate that. :(

A large part of it is the obnoxious monetization and general enshittification and privacy violations, but that's not all. There are a number of usability annoyances. If I've been away from Discord for a little while and try to continue where I left off in a thread on a server, it never properly preserves where I last stopped reading. There are often times when I get notifications but it won't actually take me to the relevant message, and that can even result in situations where the ping just gets lost entirely.

Then there's things inherent in Discord's design and how people use it. It's become a tool that people have decided is a convenient replacement for chats, wikis, and forums - but it's a shittier version of all of those things. Pinned messages are such a tucked away and half-baked feature. The fact that people are using Discord both to organize and discuss projects - as well as using that same space to host documentation or other critical knowledge-bases has made information significantly less accessible. I don't want to join someone's niche club just to "learn more." If I want to read something I would rather just go to a wiki on the actual open web.

Discord is hot garbage ultimately for the same reasons as Facebook. It's trying to be everything to everyone, and dropping a black box on the open web by doing so. It's just another example of people trading convenience for actually using the appropriate tools for the kind of job they're trying to do.