Earlier quoted context omitted.
The average square footage of a Parisian studio would make NY’s tenements look downright palatial. The average NYC studio is 50 m^2. The larger end for a Parisian studio is given to be 35 m^2.
On the other hand, there's nothing forcing you to live in intra-muros Paris. I live in Nanterre, 5min away from the RER station, and my rent is 1200€/month for a 2-bedrooms apartment (50 m²). I have a Point is, you can have affordable-ish rents in a business center without building humongous high-rises everywhere, as long as your public transport network can support it.
There's nothing forcing you maybe, but plenty of people will be stuck there because of circumstances.