Play as the Apprentice, Vader or Yoda and you'll see what this mechanic would be like in a SC game. It seems like almost nobody ever pays attention to that force gauge and they end up running out and standing there stunned and wide open (though you are probably talking more of a traditional gauge that either lets you do the move or not). Or even at an extreme stretch of the definition, Hilde's charge moves are sorta like this as well. For the real extreme, the special vs activation ability things serve this role, using the soul gauge as their charge mechanism.
But, here's the questions you have to ask yourself about this:
-How do you gain gauge? How fast? How much do you start with? And how much does each move take?
-Does the gauge persist across rounds?
-What happens when you try to use a move that you don't have enough gauge for?
If you gain gauge by hitting the other guy, then it becomes harder and harder to make a come back. If you gain gauge by being hit, then it becomes easier to make a come back, and leads to really strange strategies of purposefully being hit or blocking to gain that bit of super or push you into a health range where your gauge counts upwards constantly.
And, really, the soul charge system from the previous games basically did this. Though it just gave moves additional damage and properties. It has the benefits of being somewhat risky to do (depends on if you can block or move around while doing it), being able to be done equally by either side, and doesn't have any strange strategies or negative feedback loops associated with it.
