I'm not OP, but https://www.reddit.com/r/AskHistorians/ is a good example.
I always felt like vommiting when I saw people recommend /r/woodworking, but I couldn't figure out why. I was reading an unrelated critique of /r/fitness one day and somebody summed up my feelings about /r/woodworking perfectly
"/r/_______ is a bunch of beginners masquerading as experts."
Q: Does this keyboard support Linux?
A: The keyboard is advanced but you can not run Linux on the keyboard.
This is probably not what most people think of when they are looking for serious and in-depth Linux discussions.