https://wccftech.com/m1-battery-life-impressive-mistaken-for-a-bug/

The M1’s performance and power efficiency numbers are unlike anything that competing laptop chips can offer. Apple’s M1 MacBook Air and M1 MacBook Pro bring forth double-digit battery life that has been praised by critics consistently. There even came a stage that the battery life confused the company’s marketing head to the point where he thought it was a bug.

Tim Millet, VP of platform architecture spoke to Tom’s Guide and said that Apple's main goal was to make a chip that did not match Intel’s performance but beat it.