It's really not. I've had my eyebrow lines done a few times - they get bushy, but the more you do it, the less willing the hair is to grow back.
Then again, plucking my eyebrows (or my hair in general) never really hurt much either, so maybe I'm a bad sample case.
This one time, I got stung by a bee - the skin for about 5" around the sting site (inside of my thigh) swelled up and got really... rubbery?, and the hair... I literally just rubbed and the hair came out. It grew back though.
Beestings are bad.