Modern life depends heavily on hydrocarbons from crude oil. Petrol, diesel oil and kerosene fuel cars, lorries, trains and aircraft, so the transport of people and goods relies on them. Fuel oil and natural gas are burned for heating and to generate electricity. Bitumen is used to surface roads, lubricants keep machinery moving, and the petrochemical industry makes plastics from crude oil as a feedstock.
Crude oil is a finite resource. It formed over millions of years, but we use it much faster than it forms, so it is non-renewable and will eventually run out. Using it as a fuel also leaves less of it to be used as a feedstock for making plastics.
Because supplies are limited, people need to develop alternative sources of energy and materials. These include renewable energy such as wind and solar power, electric vehicles, and recycling plastics so that less new crude oil is needed. Decisions about how fast to change involve weighing cost, convenience and the future needs of society.