But the point is you can't put *more* wind turbines there. You built 400MW nominal power and occupied 70 km虏. For 4GW you need 700 km虏 etc, for 40GW - 7000 km虏 etc. And you will only get 30-40% of that on average.
This is why DESERTEC planned to build solar panels in Sahara which was good idea in theory... but it failed.