These remind me of the post-1906 earthquake shacks](https://sf.curbed.com/2017/4/18/15333168/sf-quake-shack-houses-camps). Better built attached housing would likely let people live better at a similar, if they could manage to agree on reasonable rules about living just a bit closer.
Mostly if you live in one, you own the house but not the land. This means the landlord takes the bulk of the equity instead of the trailer owner