What is the point of psionics?

In almost every case I can think of, psionics exist as a lore based reskin of traditional magic but are still basically the same thing. You have a limited resource of them and they allow you to do otherwise impossible things.

What is the point of this? Why not just have a psionic discipline of magic? In a sci Fi setting why not just have it magic, since that's still what it is. 95% of the time they are the same thing. It seems like pointless overhead that is now shoehorned in as a reference to older games.

So I'm not talking about the historical reasons from settings like dark sun or others that need to call out the was they differentiate themselves for mechanical reasons. They are basically redoing magic all together for their setting. I'm wondering how it could be used if RPGs were being written for the first time today. Is there a system that has used them in opposition to transitional magic in some way? When is it worth it to have a distinct system? When it matter more than once every 10 sessions?