It is only 15 miles to the nearest campground, 100 to the furthest we frequently use. Even going out for a week once a month, ten months a year, about 1000-2000 miles a year. That's for us active campers who don't have to work.
Families who use RVs for vacation road trips, might have one two-week vacation a year. Most often that's a few hundred to a couple thousand miles. To cover more miles than that, one would be driving more than four hours a day for the whole vacation, that doesn't leave much time for camping and other family fun stuff.
Retired, I can do a 3-4 week trip. For me those have been 2000-5000 mile round trips, one or two on the years we did them (but we also liked to do overseas travel and cruises 2-5 weeks). From the middle of the U.S. most of the places we used as road trip destinations have been less than 2000 miles away, not like being on one of the coasts or stuck up in a corner of the nation.
Snowbirders? Most are in fivers or larger A's, but some use C's for winter trips to warmer places. One round trip a year. My cousin's trip, southern Michigan to South Florida, is about 1200 miles. My snowbird trips to a warm part of Texas (Houston, Galveston or San Antonio) have not been much more than 500 miles each way.
My motorhome travel has added up to 35,000 miles in 10 years.
How many miles a year have you been pulling your fivers?
Yes, cost of motorhome ownership is high, fixed costs often push lightly-used RV per-night costs well over $100, can be well over $1000 for a million dollar coach. It is almost always cheaper for me to stay in motels when I travel, but the RV isn't about trying to save money on travel.