What is likely to happen is change in political will to keep the ban - you know, the usual bribery and the talk of “jobs” etc. That is a bigger threat than oil shortage
The best option is to develop means of providing energy which disrupt the economics of even oil extraction/refinement. Nuclear could do this - uranium occurs at a pretty constant rate across the earth's crust. Nuclear could also be built out at a rate of choice to meet and pass the energy provided by fossil fuels. One thing that typified the industrial expansion to modernity is ever increasing utilization of greater amounts of energy. Energy storage even has suitable options to disrupt fossil fuels - vis a vi hydrogen fuel cells, lithium batteries, and plenty of other options. (Personally, I like that fuel cells output water since desert areas are seeing greater population characteristics.)
In short, the best option is to leave oil and fossil fuels in the ground and grow the world off its use through appropriate investments in tech and infrastructure.
Even the term “fossil fuels” is an inappropriate framing of the chemicals involved since it restricts their use to burning. Consider the processes involved in their formations: organic material grew for eons millions of years ago. It then had to be buried in just the right conditions and later embedded into even further beneficial conditions. It took millions of years, high temperatures, and high pressures to go from plant material to these complex molecular forms. Then we dig them up or seep them out with fracking and further refine them. Then we burn them. Huge losses of energy all along the way. Using oil as fossil fuel is a huge waste of the energy it took to create those molecules.
We may not have reached 100% on each, but we've changed a lot. We have other values than money.
Solar allows us to keep doing some things that oil powers, but we would stop using oil at some point, limited by pollution killing too many of us, running out, or choice.