> This might turn big suburbs from food/culture deserts into the default places people want to live as they have more space for cheaper
This will certainly not happen. The reason these places are culture and food deserts is precisely because people drive everywhere and the driving infrastructure requires so much space that it is impossible to have density at the levels needed to support culture.
I'm really doubting this is the case. It seems much more likely to be due to zoning laws.
It already has!
Ethnic food has thoroughly suburbanized, as has shopping.
Even just paying for the roads for these cars to drive on is a challenge with the lack-of-density they require. So many suburbs with large lot sizes just learn to live with the potholes.