In full battlemaster gear if I get focused and can't freecast I'm dead very fast.
I usually (by the smart players) get focused and if by 2 or 3 people I'll be dead very fast. I can flip turn stun, whirlwind, root... I can shield and force run but I'll get chased down stunned and killed within a matter of seconds if they do it right.
If that happens it makes the difference between me doing 100k damage and killing 10 people or doing 300k damage and killing 50 people.