I'm past the edit window here, but have a couple more thoughts. First, I'm just a jazz player, so my gigs can get loud, but not screaming stooopid loud. Second, I am almost always amplified on stage, meaning that the most delicate subtleties of optimal tone quality are lost anyway.

Many of the rock players are moving to in-ear monitors, which block everything but replace it with your monitor mix, received via wireless.

On the other hand, some band mates, and my kids, play classical. Their needs are a lot more critical in terms of perceiving their tone quality. A benefit of the fitted plugs is that you can get the capsules with less attenuation, which means you're still safe in something like a classical ensemble, but without losing too much.

Under $20, nice: https://www.etymotic.com/product/etyplugs-high-fidelity-earp...

Yes, +1 for etymotic. I’ve used them for years.