My kids can talk at 80dB; I can't imagine how you'd have an indoor sound level limit of 80dB.
One time I visited an ear nose throat doctor to deal with pain in my left ear
They asked me if I had a noisy workplace
I told the doctor I taught kids. She burst out laughing
I think it's funny that venues hand out earplugs. How about just turn down those volume knobs, eh? (Although to be fair: sometimes that doesn't work; we have a sports venue around here where the crowd gets up to 116dB... you really do need hearing protection to go to those events.)
You get three problems where I am with music venues
1. Bad acoustic design. We've got some absolutely gadunkus places with god tier acoustic design that were made for orchestras or choirs 1000 years of darkness ago and most of them were designed to make it easy to hear a tiny flute or some castrato harvested by the catholic church even in the back rows of the audience
2. Crowd vibe is a real thing. I remember seeing the Hu in Wales and in London. In Wales the venue was much smaller, quieter and the crowd fewer. But it was 25% metalheads, 25% Uni students, 25% the Welsh Mongolian community and 25% pensioners. Best night ever. The London crowd was just large, passive blob of very tired guys drinking overpriced beers whilst their girlfriends rocked on by themselves. When it came to sound the Welsh crowd were in sync with the band, the London crowd wasn't feeling it. You raise the volume on the shite crowds the crowds just get noisier - not in the same way as a crowd getting louder. Just noisier. Like random noise. People shouting because they can't hear their friends next to them, amplified by a million people. Then you get the other end of the spectrum where you could probably go acoustic for a Taylor Swift, K-Pop or Cold Play concert to thousands because the entire crowd is singing the lyrics off by heart
3. Sound guys / artists who want BIG NOISE. Also concert goers who want BIG NOISE. Lots of people into music concerts, night clubs and the usual tinnitus enjoyer circles have gotten accustomed to big noise. It is what it is
Also there are studies that show more noise = more drinks sold so there's that angle. But I think it really is just big crowds overpower musicians when the venue has shite acoustics coupled with expectations of more noise = more energy = more vibes + overenthusiastic sound engineers who paid for all that bass so they WILL flashbang the crowd with bass for every penny spent
I only know some about this because of work and because I do sound engineering at our church and we try to keep it around 90dB tops during worship, although sometimes it does peak (5 second average) around 95.
Churches usually have pretty good acoustics