wing_zealot,
Since you have mentioned it and it's true as we know because we've lived on the lake Michigan Shoreline for over 73 years. Many days in a row in one state park CG site on the shoreline are very close to impossible to be had unless reserved in very early January and we virtually never reserve sites. Only twice in our 51 years of RV'ing.
We're very flexible and truly enjoy a day or two in one CG and then move to another CG and then still another as it gives us more new stuff to enjoy constantly and more places to visit rather than the same thing for a week or two weeks straight. We already live very close to the most popular West Michigan shoreline State Park and can go there anytime even without one of our RV's so maybe we are just spoiled! Per our logs, we have camped in 66 Michigan State Parks and many over a dozen times and have been in 93 of them so we are no strangers to the state park system here.
We actually enjoy moving around from CG to CG every day or so as it's far from boring or a hassle and have always found a CG site to be had in one of the close to where we are State Parks or National Parks or even county CG's/township CG's/or even a private park. Meet/met lots of different people, RV'ers, etc from all 50 states and Canada. Several are and have been very long time friends still and we'll meet up somewhere around the USA, Canada, and even one time in Alaska on one of our RV/various trips up there.
RV's have heat, cooking arrangements, refrigerators, beds, toilets and showers, freshwater, gray and black holding tanks, most have A/C, most RV's are self-contained, and under most all of them there's wheels that turn so it's really a "home" on wheels just waiting to go somewhere or anywhere, so why not? Even truck campers and tents will have some wheels carrying them to wherever.
That's what RV's are for! Others just pay thru the nose for a motel, hotel, etc and still have to eat somewhere with even more costs.