Even if we had the option to start building them tomorrow, changing the infrastructure of the entire world is costly and can't happen overnight, and we're reliant on petroleum for a lot more than energy production.
Fossil fuels would, best case scenario, be phased out rather than becoming immediately obsolete.
And the oil companies aren't as much the problem as people would like to think. If the cleanest and most abundant source of energy is not the cheapest, there will still be a demand for alternatives. Coal has long been obsolete, yet it still provides almost half the energy of the U.S. and 65% to 70% of China's. The reality is that even oil can't meet our needs. Not even close. And when better tech does come along, the upgrade from obsolete but working infrastructure to new and better things is not a realistic investment.
Anyone feel like paying 85% income tax for the next 30 years and being at war for most of it? Because maintaining the resource flow to support our needs is no simple undertaking. Getting rid of oil dependency, if we can, won't change that.