This is typical in mny state parks since Reserve America took over. Doesn't make any difference, RA still gets the reservation fees, and the reservation numbers look good. Too many people reserve every weekend they can, then either cancel at the last minute or just don't show up. Meanwhile, the park and Campground lose most of their money, on sites that have to be maintained, but are never used. Without having to pay for confirmatirmed sites like most hotels do, Campgrounds should be able to open site for walk-ins soon after a checkin-by time. Paying comfirmation for the entire reservation in advance would stop a lot of the abuse.
But, all of this is being done for the public good by paid politicians, sy folks like us have no say-so in the matter.