Tiny houses, van conversions, and even off-gridding as a concept are nice and in theory solve a lot of housing issues. The problem with them imo isn't so much the lifestyle, but the endless government meddling. From taxes to zoning and code laws, there is a lot of work and research that go into making the choice to go any of those routes and imo a lot of people are unprepared when they jump into the fad. That is the second and more apparent problem: it's been cool for the last few years to get a tiny house.
Because of the rise in interest and demand, the cost for such living has skyrocketed. It's not exactly cheap anymore. Cheaper than an average home? No question. But it can turn into a money pit real quick if you don't have a plan and most of the people you see online living their best tiny life are loaded or have access to money. When they do their cost break downs, they never even give the full picture either for the average person.
It's cheaper long term and easier too to just buy and maintain a single wide. Tiny house people love to act above the trailer life, but in reality, they're a step or two downgrade from a fucking trailer in every way lol.