It is of course correct that eventually all energy will be renewable, and the only question is how fast that happens. Fossil fuel will run out eventually.
It is also correct (in my opinion) that we should rather not gamble with the amount of CO2 that can be safely released.
The way to speed that transition up is to make fossil fuels more expensive. The way to make that happen is to mine it at a slower pace, and to keep larger reserves. As it happens, such a course of action would be highly profitable for everyone who owns fossil fuel reserves.