There was a semi-arbitrary building height adopted during the Haussmannian reorganization in Paris. My feeling is people noticed it led to perfectly liveable blocks. (Most places go a bit higher than this by now but Paris is strongly attached to the "roofs of Paris" and actively protects them. So Paris is a mix of Haussmannian building heights and higher.)
In the 50es through 70es, there was a strong need for extra housing which led to the projects outside Paris ("citées"), to many factories torn down to make space, but also to much higher residential buildings here and there. Still worked fine (well, not many of the citées worked fine).
And people really, but REALLY love being able to walk to their preferred local baker and pastry shop (out of a choice of several of course), and to the local grocery store. The density has to be high enough to support these.
Turns out, high density also allows a great subway system. Nobody complains that it exists.
In the 50es through 70es, there was a strong need for extra housing which led to the projects outside Paris ("citées"), to many factories torn down to make space, but also to much higher residential buildings here and there. Still worked fine (well, not many of the citées worked fine).
And people really, but REALLY love being able to walk to their preferred local baker and pastry shop (out of a choice of several of course), and to the local grocery store. The density has to be high enough to support these.
Turns out, high density also allows a great subway system. Nobody complains that it exists.