power leveling jacks

Just curious, I've been in situations where my tires were off the ground and never had an issue. I mean where is the RV going to go? It's still on the ground via the jacks. The jacks have a footprint about equivalent to a tire. The jacks would have to laterally collapse and then it would drop to the tires anyway. I seriously doubt there is a risk of it skiing down a hill on the jacks. And they will only extend so far thus inhibiting you being on a step enough incline for an issue to occur. Sorry I just never understood the "tires have to be on the ground" thinking. I see lots of folks at CGs all the time with tires off the ground. I've never seen an issue where it took off because of it. Not trying to be crass, I've just never seen or heard of an actual issue. If you use your jacks, and then add boards under your tires, what's the point of the jacks? You might as well just have leveling boards and drive up on them.