To cast a spell. To change the shape of the world. To call upon strange powers and have them do your bidding. Magic, is the fuel of change in so many RPG universes. Even if you don't call it magic, such as nano powers, super abilities, etc it all works out the same. Magic. Something beyond conventional science and logic. Quantum changes to the universe that just IS and DOES. The Force if you must.
Either way the player uses magic to rewrite the world's order to their own will.
The catch is each magic system has to fit the world they are built into. I've seen many 'bad fit' systems over the years where the powers don't flow into the narrative of the universe. Case in point d20 versions of The Force from various Star Wars games make The Force work far too much like D&D spells. You can't have fire and forget when dealing with the Force. You need to have a always on, but narratively dangerous system. One that pits the abuses of the Force directly on the fate of the character. Dark Side and all that jazz.
Another bad fit would be MAGE in the rest of the oWOD setting. Don't get me wrong. MAGE worked well on it's own. But not only does the darker nature of the WOD demand that MAGES are limited by harsher paradox but it also caused some of the biggest magical headaches in the early editions of the games. MAGE was ground breaking, and worked well in it's own work, but REALLY didn't play well with the rest of it's kin. (Like Blood magic and Gifts.)
Generic systems have the square peg in round hole system where narratively the powers require justification if they don't quite fit the setting. GURPS suffers from this. Effect based systems like HERO and M&M are a little friendlier but run into mechanical issues where there is no thematic support for how the dice and player build magic. (Unless you obsessively add layers of complexity by building crazy detailed if/and requirements into powers.)
One of the few 'good fit' magic systems was Earthdawn. The powers in that game were tailored for the Adepts and worked like advertised. Enhancing existing skills, opening up stylish power sets unique to each, but having enough cross play to use similar sub systems. Things like Thread magic and committing health for defense with magic items was very iconic to the setting.
Then there was Poker like mechanics in Deadlands where you 'draw' against powerful spirits in a game of chance on invoking their abilities with out unleashing their fury on yourself. It was a good fit to the wild west setting and made the 'drawing' of cards a tense thing.
I'm not saying with some TLC other systems can't fit into what you need, or Generics suck at magic. Because neither is true. D&D style magic works in D&D style games, but not say for psionic powers in a space setting.
But before you saddle up with a new game system that uses a type of magic sit down and look at how the magic mechanically and thematically works in the setting. Is it a good fit? Does it have "Fidelity" to the genre and style it's trying to emulate.