£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.
Or listen to genres where 99% of artists will never reach mainstream popularity and charge these kinds of prices. For example Lorna Shore is currently touring Europe with Rivers of Nihil, Ingested and Distant. Most shows have been sold out for months, in nice venues, and yet I got tickets for the Paris show for 35€.
That's partly it as well! It's fun to explore artists and genres who aren't super mainstream.
Although sometimes it's just artists who aren't likely to be that well known. I saw Asgeir in Bristol for less than £50 - he's pretty mainstream I'd say (>700k monthly listens on Spotify) - he just happens to be Icelandic and performing in his mother tongue at least half the time.
I (and plenty of people I know) regularly attend live music, with on the door prices that are equivalent to the cost of a few drinks. But equally I've been prices out of seeing some of my favourite acts because they're big enough to demand higher costs so I totally get where you're coming from.
I think what I'm getting at could better be phrased as; people don't want to see small acts much these days.
There's loads of acts like Ed Sheeran, but if you're into Ed, not just music like him, it's going to seem like it's impossible to watch it live, when in actuality there's a lot of gigging musicians who are out there with accessible performances.