I am not trying to be an apologist for RA, but I don't feel they should take all of the blame for various fees.
For example, in Florida there is a $17 cancellation fee charged by the state park system, not RA. Each state makes their own rules. Even with a heavy cancellation fee, some Florida parks are so popular that campers reserve multiple dates 11 months in advance, and are more than willing to pay the cancellation fee once their actual dates are finalized.
RA is certainly entitled to receive a handling fee for their part of the transaction. They have to get that either from the camper, or from the campground. Prior to 2015, the state of Florida paid the handling fee, and the camper never saw it. In 2015, the state of Florida decided to pass the handling fee through to the camper. More money for upkeep of the parks and campgrounds.
It looks like RA is now handling state parks in 31 states. As a retired businessman this suggests to me that they have a good business model which is fair to everyone, but is, of course, especially beneficial to the parks. Each state has the ability to add any additional fees that they wish. Extra vehicle fees, weekend surcharges, change and cancellation fees, electric fees, dump fees, and on, and on.
If you don't want to use RA, you will limit yourself to drive-up sites in 31 states. I don't recommend that for Florida, especially this time of year.