Hi, I just wanted to ask Tank mains out there how is it like?

In most games I played I play a healer because the way I think is:

Dps - Long queue times
Healers - Short queue times
Tanks - Short queue times but hard to play

But it seems like now at least for me the healer queues has gotten longer so I was thinking to start leveling a DRK because it started at 30 and tanking while leveling doesn't seem that hard. I want to know how hard tanking in endgame content is. Is it hard to learn? Like when to use cd's and other mechanics. Because as a healer its just heal anyone who isn't full health and dps if you can. (also for anyone who plays dps also how bad are dps queues?)