It is, it's just massively time-shifted.

It's interesting to put that in perspective: the pyramids were built out of solar energy by way of muscle. Skyscrapers are built out of solar energy mostly by way of diesel fuel.

Fossil fuel is a solar battery; charged in a couple hundred million years, humans will drain it in ~500.

No wonder we're seeing exponential growth with that injection of stored energy into society. The industrial revolution is a coal-powered nitro.

Checkout this explanation of fire by Richard Feynman - its a really eye opening perspective

https://www.youtube.com/watch?v=N1pIYI5JQLE

He explains the light of a fire is just the light of the Sun, it's just been stored in the wood

By causality, it kinda is.

It is. Except for geothermal energy brought on by radioactive decay, all energy on earth originally comes from the sun. Fossil fuel is sunlight that was absorbed by plants which then either decomposed into fuel over millions of years, or were eaten by animals which later decomposed into fuel over millions of years. Our cars are powered by very old, stored sunlight.