we could also use nuclear propulsion, which the russians have been able to successfully do with cruise missles
There are lots of alternative energy sources, but we haven't managed to switch to them with our pretty advanced science and energy, so there may not be a developmental path for less advanced societies that ends in plentiful energy sources without fossil fuels as a stepping stone.
Put another way: If a society at the level of pre-industrial revolution Europe didn't have access to oil and coal, do you think they could have figured out nuclear energy? How would they obtain the energy to process and refine fissionable material? Or even for that matter... how could they obtain the energy to smelt iron and steal, let alone build computer chips and solar panels.
So our failure now also limits what any successor intelligent species could accomplish (until enough fossil fuels can form again).
There's a question then of whether we'd have been stuck on a pre industrial ladder rung if it hadn't happened.
It just seems necessary, but of course the opposite might be true, that if we didn't have this easy energy we'd have jumped ahead with solar and wind or others instead.