Welcome to the forums - but don't expect a lot of sympathy.
Reserve America is one of three companies that I know of which is in business to handle campground reservations.
The reason your state went to Reserve America is that the state parks will actually get more net money from the contract. The costs of running their own reservation system was likely higher than contracting out. But those fees are passed on to the people using the state parks.
Many people keep saying that non-essential government services should be contracted out. Reserve America handling your state parks (they also run the federal Recreation.gov system) is just part of letting private industry do a 'better' job than 'government bureaucrats'.
Though the actual costs for the person using that government services has to pay more money.