Agreed... I don't make reservations and often 'look' for first come/first served campgrounds. While working in the Carolinas, my favorite such park was
Ebenezer due to it's proximity to Charlotte, NC and surrounding area. However, due to it's low camping fees at the time and location on the lake, locals severely abused the first come policy during the camping season.
Since the Ranger came around to collect fees in the late evening, a camper leaving in the morning could leave a pup tent on the site for a friend arriving late in the afternoon. Of course, an individual arriving in between assumes the site is taken, negating the first come policy. Plus, I have seen a pup tent sitting on a site for 3 or 4 days before someone arrived in a RV to occupy it. Someone obviously paid the low fees. But that negated the first come/first served policy. That went on for years. All that has changed. The county raised the rates 160% over night a couple of years ago making the park less desirable for anyone other than the leisure camper.