Another aspect to bring into the debate is the personal cost of caving today compared with when I started, back in the 60's, then it was any old warm clothes with a hand-me-down boiler suit to keep it all "Tucked in", boots you couldn't care about, a cadged old miners helmet, and a "stinky" or if you could afford it an old Oldham miners lamp (about the only thing you had to pay a significant thing for). Clubs supplied ladders & lifelines, a good club would offer you loan of a reliable light. As you progressed you might invest in a "Goon Suit" or a home made wetsuit.
Nowadays, personal expenditure includes undersuit, oversuit, high power specialised light, wellies of your choice (wellies were onced frowned upon) harnesses left, right & centre, descenders, ascenders, etc. etc., the expenditure on personal caving gear bears no comparison to what it was then, in those days you joined a club to get access to ladders & lifelines, and get down holes.
If I where to go down P8 today using the same equipment as when I did it for the first time over 40 years ago, I would be either;
1. Berated off the planet.
2. Banned from caving for life.
3. Ostracised from any caving organisation.
4. Slated to within an inch of my life on this forum.
Point is that the cost of personal equipment nowadays mean that teenagers (as I was when I started) consider they have "better" things to spend their money on than personal caving gear.
I cannot deny that progression in techniques and equipment have led to uncountable discoveries but the point I am trying to make is that it is not so easy for youngsters to get started as it was in my day.