You can get a pretty decent house in some rural economically depressed parts of the USA for $100k, if you look. Use zillow, set price ceiling to 100k or 110k, 2BD and 1BA or 1.5BA, start browsing map to random small towns in the midwest and prairie states.
You can get a house in economically healthy cities and suburbs for $100k...
... as long your definition of economically healthy doesn't mean "top-tier school district in a trendy metro area", and your definition of house isn't "4bd/2ba recent construction"
Sure, but my suspicion is that the main driver for someone doing this is the allure of moving to a different country, especially one with such a reputation of having beautiful scenery and culture.
You still can get a house for that much in Detroit, however you'll potentially be living in a dangerous neighborhood. Safe Detroit neighborhoods have actually soared in cost even if they aren't in the downtown area, believe it or not.
If I were to do something like that for habitable, ready to move in house under $100k in some post-industrial economically depressed city, it sure wouldn't be Detroit with all the big city problems that come with that... Somewhere much smaller like Oswego, NY or Elmira, NY.