Exactly. There was a Kirsten Dirksen video showing some cabins built on a piece of property that was zoned (I think) for mobile homes. Voila', they welded some big wheels on the bottom of the structures.

They still seemed poorly laid out with crummy bathrooms (in this case, no piped water and a terlet that was basically an indoor plastic porta-potty) but I did admire the law-skirting.

There can also be avoidance of property taxes in some states I believe.