GPS doesn't use battery; a better description of users is they do completely random stuff because they think it might increase battery life or they dreamed someone told them to do it once years ago.
Killing apps after they're done with them is the other big one there.
Tell that to my phone. And my sports watch. GPS being available doesn't use battery on its own, but if apps actually ask for precise location information so it gets used, that doesn't happen for free power-wise.
Killing apps after they're done with them is the other big one there.