I think you are either too wealthy or too attached to city living to understand the point of these.
Tiny homes:
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are affordable to anyone with almost any income, not just $80-100k+ a year incomes (which are practically mandatory now to buy a home in the current economy)
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Can be set up literally anywhere that zoning allows for
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A good choice for off-grid/prepper lifestyle
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A good choice for solo living or for a couple to share with no kids