I'm not sure what evidence you have for these assertions, or whether this is just subjective prejudice.
However, I'm 62 (so on strict grounds of age, at least, probably "grown up", although I'm happy and proud to call myself a socialist, and have become more so as I got older).
I also would...
You don't live in Brighton though, do you? Plenty on sale here - in some newsagents and supermarkets, looking at the relative size of piles first thing in the morning, it is clearly the largest-selling paper, certainly the largest selling quality paper.