Exactly. The whole point of CTFs is that you could start on a simple one (CSAW was usually my go to one to recommend) as a complete novice who'd never done a second of computer security work and, after a few days of 8+ hours of running into concepts you hadn't encountered, googling, reading tutorial, practicing, overcoming the challenges to get a flag, etc., you'd come out the other end knowing a solid bit of security practitioner basics and likely whether you'd like to continue. Then you could keep going upwards and onwards. I went from 0 knowledge to a nice job in the field in a year.

Raising the difficulty only matters for the (imo) less important part: the dick measuring competition between the very top teams.

The actual point of CTFs was usually to keep your skills sharp and stay learning. Eventually you build your own challenges, thereby completing the "have it taught to me, then do it myself, then teach another person" three step process towards mastering concepts.

You can just say "let the people who want to learn from it do so" but honestly the entire culture of learning in the US at least is DEAD. We turned "education" into a rote system of maximizing incentives to the extent that that's all the youth know it as, and (increasingly) all educators can do. It's just gone without some kind of major reckoning, and we all know things will just collapse before that happens. The ball is in the court of whatever country can learn how to force its youth to learn the real way and use AI productively only AFTER learning the concepts it's being used to accelerate.