Wanna really quick proof?
We still haven’t run out of trees or whales.
I agree that we should use an energy source that is “the best”. And by “the best” I mean the one that most people wanna use. You can still heat your home with wood; most don’t wanna. Why? It might be that it’s too expensive. Maybe it doesn’t do a good job heating the whole home. Maybe it’s because it is a lot of work and is messy. Who knows. But you can if you want.
You could also work on warming your home with solar. Heck, you could even try to create your own electricity with solar. Why don’t we? Because it’s expensive to do it. Plus, you don’t really get off the grid; it rains or is cloudy. Not to mention it gets dark every night.
When the time comes, and it will, we’ll either find the perfect energy source or we’ll find more oil or we’ll drill in places we haven’t yet.
And long before we’ve taken every drop of oil, we’ll have made the switch.