This is something I really agree with. I feel like encouraging people to actually cancel their reservations so that other can use it would be a big help.

I see it working this way: keep the fees for camp sites reasonable, and you get most of it back for cancelling 2 weeks out. As you get closer, a prorated added cost to cancel. Fail to cancel but don't show? 25% no-show fee applied straight to the card on file, automatically. Watch the behavior change overnight.

I don't think it's about building new sites. If anything, the NPS is closing stuff down because they can't maintain what they have. I know of two car campgrounds in Washington state that are now hike in only because the road washed out, and the NPS decided not to rebuild.

Also, if preservation is the goal, why would they build new stuff? Building a bunch of new roads and sites, toilets, power, etc., that doesn't really preserve the natural environment. This is part of why I like the Olympics and North cascades: there are parts available to those who just want to drive up, but the majority of the park is well preserved and has no road access. But I also accept I'm biased as a hiker