That's what they want us to believe, there are a lot of other sources of energy or fuel but they don't like it because they don't make a lot of money out of it.
The fact is that almost everyone uses oil today, and almost all economic activity will be crippled if the supply of oil is short or stagnates, so this business is huge. even today we can also see Aramco is one of the companies with the largest market cap in the world