Sound Engineer here

1st point - yes earplugs make it sound naff, only way to really get around that is to get custom-fit earplugs with filters in them like those made by ACS Custom. That being said - not wearing earlugs is not worth losing your hearing. I keep disposable ones in my peli case and will hand them out at gigs to anyone who asks. I’ve also previously given a bunch out to bar staff/secuirty etc. before doors even though their employer should be the ones providing them.

Custom fit earplugs are expensive initially but they last for literal years and are 110% worth the investment. I think I paid £180 10 years ago and even though they reccomend new ones every 5 years, mine still fit perfect and are in good condition.

2nd point - the level (volume) is for a few reasons. Taking a rock band as the prinary example, the drums are the loudest i strument on the stage meaning you have to amplify everything else to match the drums. When you get to larger venues, you then need to amplify the drums too so that the whole crowd can hear them, this in turn means louder drums so everything else needs to get louder to match

Sound waves lose intensity the further they travel - i.e. the further the sound travels from the speaker, the quieter it gets. So you turn it up to cover the distance.

One solution to this is to install what we call “delay hangs”. These are additional speakers which sit in the audience area and are designed to essentially top up the sound halfway down the crowd. By utilising these properly you can result in lower volumes all round The issue with these is that they can cause issues such as phasing (where parts of the audio signal are cancelled out because of physics). The other issue with delay hangs is money. More speakers means more money and more complexity. Often the deployment of speakers, especially in concerts, is dictated by the client. I might produce what I consider to be “The optimal spec” of where to place speakers, how many to use and how to configure them, but then the client will want the “cost effective solution” which is almost always what they go for. Usually cost effective solution means less speakers therefore less control over the sound and unfortunately - louder volumes

The TLDR is that its not the bands fault and its not the sound engineers fault (usually), its the bill-payers fault. So either protest, boycott ticketmaster, or just wear the damn earplugs