As an isolated unit here and there, a micro apartment is fine. It meets a market demand.
But to have an entire building of micro apartments is a disaster.
It wouldn’t take much for a building of micro apartments to become a brothel, a drug den, a place for single moms with multiple irresponsible children, etc.
More likely it would be filled with young careerists. My only trouble with it would be the hard partying on Saturday night.