I'll give some suggestions that I am sure will be unpopular. But at some level of implementation, they would help.
1) Raise prices for campsites until there are vacancies.
2) Raise prices for the geezer pass. A lot.
3) Experiment with demand pricing, like say airlines do. Offer some spaces at high prices for people who aren't willing to jump through all the reservations hoops far in advance.
I am 58 y.o., and I am sick over the current situation. We've never been to a NP, and we dread dealing with all of the problems that this thread is about. For once in a lifetime to say Yellowstone, I'd gladly pay $100 a night if it meant we can get in when we want to and without playing reservations roulette a year in advance. I've piddled away more than that on dumber things. And I'm a cheapskate! But, there is value to me in being able to actually see the park once. It's no different than buying tickets to a championship game on StubHub for a once in a lifetime. When the demand is so much bigger than the supply, something has to give.
You can say it's not fair. Is the present system fair? Really? The present system rewards people who know how to play the game, and are willing to. It's not as if the park CGs are full of orphans and their minimum wage foster parents. I'm sure for most of the campers, the camping fee is a minimal part of their trip costs. People pay a LOT to camp at Fort Wilderness. Why not pay a lot to camp in the real thing?
It's like places with rent controlled apartments. It's great for the lucky few that have them. But it stinks for everyone else who'd like to live there and is willing pay a normal rent.
Raise em to the market price, whatever that turns out to be.
:)
