My question was more about the fact that we're still burning extreme amounts of carbon purely for energy, not for density of energy or density of power or portability of engines - we're burning coal for electricity, we're burning gas to heat homes.

We'd need to pay back all that energy, but in the coming decades we can't even afford the energy cost of the relatively much simpler solution of "simply" not burning bulk carbon for heat.

I don't think new coal plants are rational at all.

Re gas heating, I sure could've used some just this past winter during the Texas snowpocalypse. My apartment uses electric power for heating/cooking, so electricity was a single point of failure. Resiliency through diversity is a point I missed above.