I definitely think that people are being priced out by col and this is very unfair. But I also think some posts on here about how unaffordable West End theatre is are exaggerated.
The Globe offers standing room for as low as £5 or £6. OK, it's not ideal as most of us would rather sit down but it does at least mean a lot of Shakespeare & some others is affordable if you're prepared to stand.
Then as to West End musicals : I think an issue here is that pps who cite them as unaffordable are trying to take a whole family, 2-3 or maybe more kids, as well as them & DP. This will be a lot harder than going on your own or with one other person, especially if trying for an Xmas show (though booking in advance might slightly lessen). It does vary based on show too : the most popular will of course be more likely to be sky high.
COL has obviously increased a lot, but I also wonder how affordable West End was in the past for family trips. I was born early 2000s and my mum was able to get a lot of cheap tickets very high up just for me & her. As a child her family didn't really do musicals or plays. In the 70s-90s, were big shows a lot more affordable for family trips?
So I suppose I'd say that I agree prices are too high for a lot of families, and this is wrong : but I'd also caveat that I think there are lot more affordable options than some posts on here imply.