We do make reservations in advance for our RV trips because
A) trip planning is part of the fun;
B) Some campgrounds/RV Parks have especially nice scenery, convenient locations for fun activities, historic significance, and good reviews. Sometimes (not always) those are inside national or state parks so are inexpensive, too. Such sites tend to get booked up very early;
C) There are a lot more campers now than there were few years ago competing for the same number of sites. It makes road trips more relaxing to set out in the morning with a confirmation already in hand down the road.
However, when we start driving back home point A to point B, we just decide each day how far we'll feel like going before stopping. Still, we usually call ahead by mid-afternoon to book a site.
