I can see both sides of this, and I wonder if the real damage on stage comes from amps and foldback speakers. All the data I've seen about noise induced hearing loss is based on long term expisure to continuous sounds, like machines in a factory for an eight hour shift.
I've tried playing with various types of earplugs lately, and I just can't play properly if I can't hear the others around me. I also need to judge how loud to sing backing vocals, etc. I've never had ringing in my ears, but since turning 50 I've noticed a slight tinnitus pink noise at night, and I find it hard to hear conversations in noisy environments. So:
I wear earplugs during breaks, so I don't have to listen to DJ's and loud crowds all the time.
I sometimes wear just one earplug on the side where my hihat and foldback speaker are.
I only have vocals in my monitor, not drums, and I keep it as soft as practical.
I've found some earplugs which don't cut upper mids so much, and I can sometimes get through a whole gig with these in my ears (earasers) without getting lost and making stupid mistakes all night.
I always wear ear muffs when I'm practicing at home. I quite like the warmer, muffled tone, and the sense of isolation helps me concentrate. The ear muffs also remind me how much I usually recoil and brace myself for loud hits. With the muffs on I can play fast, loud passages in a much more relaxed manner.
But most of the time I still perform without earplugs, because I need to listen and communicate with the rest of the band.