KISS: Keep it Simple Stupid.
Same rule of design for most things.
There's a reason most games have some kind of weapon-triangle (spear beats sword beats bow); rock-paper-scissors is timeless.
Make up something unique and cool. Put it over something proven and true.
Voilà. You have a good power system.
Make sure anything you do, it serves the narrative of your story.
In Mutant City Blues, a detective + Super Hero RPG, every power is connected to nearby ones on a power map. And some powers are connected with mental health issues (anxiety, etc.)
This is meant to help the players determine clues on a crime scene.
"Someone used a pyrokynetic power here. And this car was clearly picked up and lifted off the ground. Fire powers and super strength are too far apart-- it has to be the work of at least two mutants!"