This is why I think that we should resolve the climate change crisis by reducing excess atmospheric carbon by seeding the oceans with iron. Oceanic iron seeding results in plankton blooms that consume atmospheric carbon. When the plankton dies, it accumulates on the seafloor. Over geologic time scales, the accumulated plankton will turn into hydrocarbons, renewing the supply of cheap fuels for a post-human civilization millions of years in the future.
We can't even switch to renewables because that would make some capital owners slightly less money and you're thinking of civilisations millions of years in the future...
Where I live, it's because the taxpayers would have to pay too much and would be exposed to a lot of outside risk (it's usually not that sunny here, and we don't have space for wind turbines nor where to landfill the replaced blades).
Here it's the capital owners pushing renewables because it's one of the easiest, cheapest, least objectionable (in case of solar) and least risky energy projects you can build on almost any useless piece of land (everywhere is near the grid in this country), but they just can't fulfill the demands of the state-owned energy company with their solar arrays and wind turbines. Hydro is out of the question, the water-environmentalists hate that - for good reasons I have to say.
There is a nearby country that "did" (legislated) the switch... In result, they are the most polluting ones in every metric (per capita, per kWh, per km^2) while having the most expensive electricity on the continent; all metrics are getting worse every year there. Not a good look for the switch, certainly doesn't make most voters in my country motivated to even try - and you'd need to convince half the country. Right now the support is around 5-10%.
In conclusion, given that both our worlds coexist at the same time - I think it's not that simple to switch and wouldn't be looking for the reason in either capitalists or states. Perhaps the technology is just not ready for a full-scale switch yet.
If modern society collapses, starting back over with the same approach isn't the best plan. Cheap hydrocarbons are sort of like VC funding. They have allowed society to advance extremely rapidly, in a totally unsustainable way. We have yet to find out if we can stick the landing on transitioning to a sustainable lifestyle. It's possible that humans just aren't wired in a way to responsibly manage the risks introduced by sufficiently advanced technology, at least not at the current rate of change.
In a post-apocalyptic world, survivors should really be rethinking the approach that brought that about. Avoiding the cheap hydrocarbon consumption phase might result in a much longer lasting civilazation next time around.
In addition to coal that I mentioned above, it should be possible to have industrial society with renewables. It wouldn’t be as high energy as ours or as industrialized. But if they knew the science and some technology they could skip the big iron phase.
Early power could come from burning wood and windmills. That doesn’t have enough power for smelting iron, but there is more than lots of iron, Electricity could come from concentrated solar, wind, hydro, or geothermal. Nuclear would be the big jump.
