• Cheap - mortgage level, not cash. They’re damn expensive. It’s a depreciating asset.
• Mobile - only if fuel is dirt cheap. You’re limited in where you can drive by their lack of maneuverability and severely limited in parking by laws and convention.
• Easy to maintain - no building codes mean no consistency, so you’re guessing all the time, and the build quality on these things is pretty awful. There’s no space to work, and it’s go the added pain in the ass of a whole truck to maintain too. And a generator. Built to last for perhaps 10 years, but with no provisions for renewal - a house roof with shingles lasts 25-50 years and is easily replaced. An RV roof lasts 10 years before sealing starts to give out if not less and needs structural disassembly to repair in many cases.

At the end of the day you’re cooking on a pull out camp stove and shitting in the bucket hidden under the couch. It’s no life for me.