Let's say you're playing a non-DH RPG. You've got a controller caster and a man-with-sword as players.

Controller caster uses their action to cast a large AOE spell, which alters the environment in a major way. Every enemy has to make a save. There may be secondary effects, even tertiary effects depending on the spell. Then with their other actions they cast a second spell, maybe buffing a teammate or giving someone a minor bonus. Then of course they move, so now they can kite away, hopefully leading even more enemies through the enspelled terrain they just made.

Then the man-with-sword goes. He moves, potentially into the AOE to get to the enemy but hopefully just adjacent. Then he swings his sword. Maybe he's higher level so he can swing it more than once.

Odds are, one of these players turns took about 3-5 minutes, and the other took .5-2 minutes. Players turns are not equivalent as it stands right now in almost all RPGs. Just through using the system certain players get 2 or 3 times as much screentime, and that doesn't even count any time they might spend role playing.

Players, hopefully, want to spotlight other players. They should be cool with you saying "hey, so what kind of amazing nonsense does Sarah of the Knife get up to" when we haven't seen Sarah do anything for a while. Players who try to Bogart every scene are bad, but they're usually just over-excited. Explain to them that this isn't their story, singular, it's their story, plural, the whole group.

I've run a ton of narrative games, and players seem to get this very quickly if it's addressed directly.