> And each of these houses costs more than 1 MM EUR.
That's the other big problem with restrictive zoning laws (other than ugliness). It leads to unaffordable housing. By saying that a house must conform with X, Y, and Z you're essentially saying "anyone who doesn't have enough money to pay for X, Y, and Z can't buy a house".
Sometimes restrictions are necessary (e.g. safety rules). Other times they sound good on paper but just end up being elitist (e.g. house must have X number of parking spaces, Y minimum size for rooms, Z minimum outdoor space). Yes, those things are nice to have. But we shouldn't price out people who can't afford them. It's better that someone starting out in life be able to buy a house with smaller rooms, than not be able to buy anything at all. We've become so obsessed with raising standards across the board that we've forgotten that the people we exclude from those standards end up with worse standards.
Also, not everyone has the same priorities. Some people might like their bedroom to be huge. Others might just see it as a place to sleep and would rather spend their money on living in a good location, or some other priority. Restrictive zoning laws remove options by making buildings converge on a limited range of designs.