Why do we feel the need for conservation more today than our ancestors did?
Our ancestors had modest energy requirements, mostly for cooking, lighting and heating. In today's society, energy consumption by humans has increased manyfold as compared to energy consumed by early humans because people have progressed. Developed nations use more energy especially for transportation and industry. Most of the energy we use today comes from fossil fuels which are non-renewable on a human time scale.
That is why, there is more need for energy conversation today than early times.
Living Science (2020, 2021)