Not always. The average car in Wyoming gets driven 24,000 miles a year something getting 12 MPG is burning 2,000 gallons a year directly and another 30% indirectly from manufacture transportation and extraction of oil. That’s a lot for a 5 year old car you could easily be saving 30,000+ gallons of oil.

Obviously, that’s average many cars are significantly worse. Run the numbers and swapping a high mileage but poor fuel economy car for a hybrid/EV and the payback can be a net positive.