Flashback!!
Earth doesn’t, in fact, have a monopoly on mean kids. You can find them in Lunar refugee camps, too.
This can’t possibly be raw Moon gravel that they’re walking on. Real regolith will kill you, tear up your lungs AND shred your feet. It’s tiny shards of glass. I like this gravel for the aesthetics, but let’s assume someone has gone to the trouble of melting it down and reshaping the regolith into a gravel that’s friendlier shapes.
Mars doesn’t have the regolith problem. Dust, sand, and rocks on Mars have been subject to wind erosion for millennia. That’s one more reason for terraforming Mars being easier than trying to live on the Moon.