Reduced skill duration passives -- when are they usefull?

What is the point of reducing skill duration? It is three passives on the bottom right of Scion star. I see on poe.ninja nobody has them. Why does they exist?

They make things like Earthquake get more dps because the aftershock comes sooner than they normally would.
Lightning warp teleports faster.

I don't know about your specific points, but i can give you an example where reduced skill duration is useful:

My earthquake juggernaut has reduced skill duration. It makes the aftershock come faster after the initial attack. Which is needed for 2 reasons:

-When you attack a bunch of mobs, the longer it takes for the aftershock to come, the longer they live, the more time they have to kill you.

-The aftershock does not work when the previous one didnt trigger yet. So you want your skill duration to be shorter than your attack speed.

Also Storm Call hits after marks duration is over, so less skill duration means less delay between casting the mark and lighting hitting it.

One way for Explosive arrow(s) to exlode is for the duration to run out.
Pods for Toxic Rain explode after the duration runs out.

Some Brands cause an effect when they detach, oneway for that to happend is for the duration to run out.

Over all there are multitude of thinks in the game that can benefit from less duration, witch is also why Less Duration support gem exist.