LFR is cancerous to the raiding community and actively turns away newer players.
Asmongold has a video on it which I think he explains very well why LFR is bad for the longevity of wow:
https://www.youtube.com/watch?v=w8ac2sQHJLI
Cross realm is kind of bad at the moment due to addon abuse. I've never felt the game was more unstable than it is now.