We just returned from Yellowstone - with no reservations. We timed our drive in to get there early, around 8AM, spent over an hour coming in the gate from the south (Tetons) because of the traffic backup.
We stopped at the first campground. We noticed numerous folks packing up to leave, and many remaining. We saw several empty sites (around 9:30 / 10AM) and picked one. We booked two days, then two more days in a row. We had that site the entire five days we spent in YS ... as we were packing up, and a truck towing a small TT stopped and asked. He just sat there until we pulled out (about half hour) and pulled in. I'm not sure if he already had his ticket, or went back and got it.
We noticed the ticket envelopes are numbered - I'm guessing that's to prove you got it that morning ? Maybe ? Not sure why it's numbered.
But we never travel with reservations - even to the major parks. We like the freedom and over the years, have only had an occasional problem getting a site and have always worked out a way to camp where we want to camp. We'd be truly disappointed if every site was 'reserve only'... that would be unfair to a lot of campers. A mixed bag is the only way to be fair to everyone.
