I've been able to always park my campers at home. I've parked on concrete, boards on gravel, asphalt, and boards on grass-dirt. Never had any problems with any surface ... ever.
Gravel has it disadvantages because weeds will eventually through it. But a good dose of Round Up every year and it keeps the weeds at bay. If you need to work under your camper, rocks are very hard on the back. - Advantage, it's easy and not costly to create a gravel pad, and rain run off if great!
I never had any problems with asphalt, with tires sinking, or anything like that. But asphalt needs to be maintained, resealed every few years, and can easily crumble under weight and weather elements. I keep lumber under the jacks and tongue, but tires are on the asphalt. Asphalt is nice, but does get very hot in the summer.
Concrete is OK too, provided it has no cracks where weeds grow through and the concrete pad is thick enough to support whatever is parked on top of it. However, concrete shows stains VERY clearly. So if by chance your black tank were to leak, or oil spilled for whatever reason, those stains can be seen a mile away. Concrete is the most expensive way to go, and depending upon your zoning restrictions, you might have to get permission to pour a pad.
Dirt is OK too. The real benefit of course, it cost's nothing. But here's the problem. When it rains, mud splashes back up on the tires and jacks and then the camper looks like a mess. If your tires are not on something solid the camper will sink in the dirt, making it difficult to pull out of the "hole" the first time.
My camper right now is sitting on asphalt with lumber under the jacks, tires on the asphalt.
There a trade of for each one, dirt, expense, drainage, and durability.
