Except it's not cheaper. 70% of the world import fossil fuels. Many changes are happening because it is cheaper to not do that and use renewables instead. US Presidents are getting involved to stop cheaper energy getting built.
Offshore wind, which is more expensive than onshore wind, is cheaper than new coal in China. New solar and onshore wind competes with fuel costs for existing coal plants.
If anything, Trump fucking around in Iran is helping the switch more than anything, such irony.