Only true for our current computers and not true with reversible computing. With reversible computing you can use electricity to perform a calculation and then "push" that electricity back into a battery or a capacitor instead of dumping it to the environment. It's still a huge challenge, but there is a recent promising attempt:

"British reversible computing startup Vaire has demonstrated an adiabatic reversible computing system with net energy recovery"

https://www.eetimes.com/vaire-demos-energy-recovery-with-rev...

https://vaire.co/

Short introduction video to reversible computing:

https://www.youtube.com/watch?v=rVmZTGeIwnc