The worst one I saw on Tiny House Hunter's was a family of four with two elementary school kids.
The "house" they chose was a shipping container with about 160 sqft and most of it was taken up with a "built-in" that had a twin size bunk bed on top and a trundle bed on the bottom. The kitchen was a microwave stand and the only sink was in the bathroom. I do believe the bathroom had a door at least. But because of the built-in, the amount of walkable space in the shipping container was about the size required for breeders to give per puppy. And anytime they moved it they would have to hire a crane. At the end of the show, it showed the trundle bed half-way pulled out and the children sitting uncomfortably on it. I think they only paid about 10k, but they were living in it in their backyard at the time of the show and claiming it was all to get out of debt. They were not in a high-rent area, so the whole thing seemed like a horrible decision and a not very efficient method to get out of debt.
Sorry, but I still think about that family regularly, that's how ridiculous that episode was.
I don't think there is anything wrong with the (very small) movement of tiny homes. I dislike the way the conversation is frequently framed. Some say they don't want to pay rent anymore and want to invest in home ownership. Others say they want to cut their expenses and save money. I don't buy either argument for the vast majority of tiny home owners. I don't think there is a solid argument showing that these homes would retain or increase in value. Perhaps they might, but I doubt anyone would argue they'd be on the same trendlines as traditional homes.
In terms of cutting expenses, it's impossible to know how many of these people are paying for their purchase. I think the general population of those who go on TV shows or appear in magazines are the types that are financing the tiny house. So you've still got a monthly living cost. Then you've either got to buy land, rent land, or rent a campground/mobile home spot. OR use Mom & Dad's backyard, which seems to be a not unpopular choice. I work in utilities, so I'm frequently curious about how these people think they can just park a tiny house on the top of a hill and have running water in their sink and electricity for their tv without paying serious bucks for the connections. I know some have composting toilets and a few have had a single PV panel, but you're not able to store that power anywhere, so enjoy your three hours of electricity each day! Others have generators, but those are not exactly cheap to run either.
I just wish everything wasn't glossy magazine stories and HGTV shows. I love observing housing trends and the nitty gritty details. I hate when they wrap things up in cliches and staging.