£100+ for a concert ticket is a real shame. I used to be an avid concert goer but that was when I could see some great acts at around £25 a go and that would be expensive 🫰.
I think a lot of the issue is that people aren't seeing as much music.
My fiancée saw Taylor Swift in London years ago when she was a country act and yeah it wasn't cheap but she could afford to go as a teenager with a weekend job who happens to enjoy country music.
The acts people want to see are all huge by the time a lot of people would bother going to see them and they know they can charge insane prices for tickets because people will pay. It's the same for theatre. There's tonnes of awesome stuff you can see for peanuts (relatively, depending on your location) but people will still pay through the nose to see The Cursed Child™.
If you want to see live music (of any genre) you can - it's cheap and easy. But you might have to go to a small cramped venue or see someone you've not heard of. Or seek out smaller acts before they become huge industry behemoths.
I'm questioning the term 'average'. There's a club in Newcastle that does a couple of free gigs a week, I'd suggest that's not an isolated case. Of course there's some big tours with £500 tickets but aren't they still pretty rare?
Yeah I'm guessing the fancy seats at a big stadium are swaying this? It's rare for me to pay over a tenner to be honest though up to £35 is the norm I'd say. But then I'm not watching Taylor Swift in a stadium.