A UI can be measured in a bunch of different ways, most of which should be measured and balanced against each other.
I recommend this video essay, where a UX professional (formerly at Microsoft) took over the UX for the FOSS music composing app Musescore and shares a lot of the lessons learned along the way: https://youtu.be/Qct6LKbneKQ
Unfortunately a lot of places use discord for things that forums used to do - bug reports for software, collecting feedback, even troubleshooting and tech support.
I imagine this is because discord servers are free while websites require money to maintain.