Anecdotes are not data, but if this is no longer true, then I must somehow still be living in the mid-2000s.
I mean I can't speak for you as I can only speak for my experience and experience of people I know.
You didn't ask for advice, but if I had any, it would be to avoid Ubuntu. Most of the poorly functioning and randomly crashing processes I've seen on Linux was on Ubuntu machines.
Straight up FUD. This isn't the experience at all. Linux had these issues in the mid 2000s, that hasn't been my experience in years.
I agree with the "inconsistency" but I see the same "inconsistency" when I open matplotlib windows (wxgtk I suppose) and they look different, only closing the window fails randomly on OS X and leaves Python interpreter running while I've yet to experience that on Linux.
Then, I'd try to kill the non-responding app, and kill works on Linux, but on macOS, it is inconsistent. And that wasn't ten years ago, that was may be two or three days ago.