[freeopinion]

I live within a 5 hour drive of something like 20 national parks. I live within 60 minutes of several National Recreation areas, State Parks, National Forests, and wilderness areas with all sorts of different designations. I'm within a 60 minute walk of at least 4 popular campsites.

It is not my experience that the USA lacks in this respect.

But if you want to visit the Grand Canyon, Hoover Dam, or Zions, or many of these other places, your last paragraph is spot on. The policy of the State of Nevada has been that you cannot reserve campsites in state parks. I think that just changed within the last year for the two most popular state parks. If you want to camp in the Valley of Fire among the red rocks or petrified forest you now need a reservation. If you want to camp just outside the boundaries, there is no reservation required and no fee. Oh, yeah, and no potable water or restrooms, etc.

Note: the Grand Canyon, Hoover Dam, and Zions are not Nevada State Parks. And you'll have to wait another year now to catch Gold Fever at Buckland Station State Park[0].

0. https://parks.nv.gov/events/gold-fever-12

Edit: Amusingly, the headline of the page at that link proclaims "Nevada State Parks Launches New Reservation System". sigh