> Do we use more electricity because of 5G? I confess I'd assume modern phones and repeater networks use less power than older ones. Even at large.

If we did exactly the same with 5G than what we did with 4G, it would be more efficient.

But why do we develop 5G? Because we can do more. It is more efficient, but we do much more, so we increase our energy consumption. This is called the "rebound effect". It's observed for every. single. technology.