Ultimately, a resource is just matter and energy transformed via human ingenuity to meet human needs. Well, the planet we live on is 100% matter and energy, 100% potential resource for energy and anything else we would want. To say we’ve only scratched the surface is to significantly understate how little of this planet’s potential we’ve unlocked. We already know that we have enough of a combination of fossil fuels and nuclear power to last thousands and thousands of years, and by then, hopefully, we’ll have fusion (a potential, far superior form of nuclear power) or even some hyper-efficient form of solar power.
The amount of raw matter and energy on this planet is so incomprehensibly vast that it is nonsensical to speculate about running out of it. Telling us that there is only so much matter and energy to create resources from is like telling us that there is only so much galaxy to visit for the first time. True, but irrelevant.
h/t Rob