I installed Ubuntu recently and my experience definitely wasn't "it just works", getting constant notifications that applications need to be restarted to update and multiple "Ubuntu has failed" popups (which seem to mean literally nothing) don't feel like it's just working to me. It actually seems like everything the OS does is janky in some way.

Even putting the OS aside I believe some of the jank is caused by Ubuntu's insistence on trying to usurp applications installed via apt to instead install them via snap. This is why my Firefox install wont allow me to copy text at random, and why I can't drag and drop files into Telegram, and why every file I download has to be dug up from some deep .snap/ directory before any other application can actually load it.