Where I live, there's a minimum income level for shared house rooms as well, and the cost of a room can be 50% of someone's income if they are working but poorly paid, so they won't be allowed it.

Luckily rooms are more likely to be rented somewhat informally, or by less stringent agents & landlords, compared with flats, so there's a decent market of these without a hard income requirement, alongside those with the requirement.