It's much more simple than that - vast majority of the world has become rich or richer by using more energy (almost a tautology), and vast majority of energy is produced from fossil fuels. Fossil fuels are still for the most part the simplest, technologically, energy source with the fastest payoff.
To get the world even to European per-capita energy usage levels, current energy production would have to be expanded 3x [1] You just have to convince a few billion and their leaders that they should remain in relative poverty for a few more decades, waiting for solar/wind/nuclear to ramp up to several times the entire current energy production. Heck, the energy production needs to expand just to bring everyone to Chinese levels, and then you would not only need to set a forever-ceiling for the above billions, but also convince a billion or so Americans/Europeans/... to become poor.
If you can't convince people to stay or become poor voluntarily, they are going to need energy. Surprise, some people are eager to sell them this energy. But it's the demand that drives the supply.
[1] https://rootsofprogress.org/devanney-on-the-nuclear-flop