> Discord is infamous for its absolutely awful UX

It's laden with ads and microtransactions, but if you remove those (shady scripts abound for those who don't want to do it themselves), the UX is one of the best on the market. There's a reason so many alternative chat clients are basically Discord clones without the microtransactions (for now).

Its open source hostility doesn't really change how well it works. You can copy the good parts without the awful parts, like so many people and companies are already doing.