Different use for different people:
About 1/3rd of the nights for us is boon docking and the rest is on hook ups. Many times we boon dock until we get to a campground and then boon dock to get home. We did a 6000 mile 3-week trip in April and 2/3rd of it was boon docking while others have never visited a campground.
Most campers with four jacks and a basement can be used off the truck and do not require additional support. Those that do will require you carry some extra shoring for the floor that will help support it rather than just sitting on the jacks.