I'm pretty happy with Linux actually. I've used a few distros and DMs over the years and honestly we're at a point in time where it's pretty nice. A more user friendly and robust connectivity management would be nice, and a few of the file browsers could benefit from a UX revamp. DMs could also enforce stricter design choices by default to gently guide developers towards a consistent UI/UX. But overall it's quite solid.
The same can't be said about most of the OSS that goes with it. Most of the apps available for Linux are garbage. I mean, they do some things well obvioulsy, but are overall terrible to use. With their crap UX and a UI stuck in the last century the only reason people use them is they have no other choice and are desperate...