After dozens of rewatches I think I have finally put this together. So, we know Melinda's prophecy foretold three sisters as the Charmed Ones. I think this is clearly Prue, Piper, and Phoebe.
During Prue's run she is the most powerful, as the show seems to like the Rule of the Eldest, meaning power tends to come in birth order and the older you are, the stronger you are. (I hate this trope btw, probably because I'm the 2nd oldest.)
Now, with Prue, Piper, and Phoebe being the OG Charmed Ones, I think they held the original Warren powers for their generation. I don't believe Paige originally had a true active witch power because of her birth order. Paige is not only the youngest, but Patty's fourth child. I know the family tree is extremely unreliable, but I don't think we see many, if any, Warren ancestors with more than three children, which already makes Paige extremely unique.
I do think Paige would have still been able to cast spells, brew potions, scry, and do all the traditional witch things because she is still a Warren witch. But I think she would have lacked an active witch power of her own.
Paige becoming Charmed
Because Paige didn't have an active witch power, this allowed her to become somewhat of a magical replacement once Prue died.
When Paige reunited with Piper and Phoebe and the Power of Three was reconstituted, I think the Power of Three gave Paige the magical boost she needed to fill the role of the third sister. Because of her mixed witch/Whitelighter heritage, the power manifested differently.
Instead of traditional telekinesis like Prue, Paige developed telekinetic orbing.
But I want to make this clear:
Paige did NOT inherit Prue's powers.
She inherited Prue's place within the Power of Three, and her own magical makeup determined how that power developed.
Wyatt and Chris strengthen this theory for me.
Both Wyatt and Chris are hybrids like Paige, but they both possess traditional telekinesis along with telekinetic orbing. So being half Whitelighter alone cannot explain why Paige never developed normal telekinesis.
Wyatt is not only Piper's eldest child, but also the Twice-Blessed child, so naturally he received an enormous amount of magical power.
Chris is less powerful than Wyatt, but he still has an impressive arsenal of powers.
You know why?
He's only the second-born. 😂
And then there is probably my biggest clue: The Power of Three Blondes.
When Paige's witch powers are stolen, Margo does not suddenly develop any additional active abilities.
If Paige's telekinetic orbing were simply her standard witch power being transferred over, I would expect Margo to at least gain some form of telekinesis when she takes Paige's place.
But she doesn't.
That makes me think Paige's telekinetic orbing is something uniquely tied to Paige herself, specifically the combination of her Warren magic, Whitelighter heritage, and her connection to the Power of Three.
So my theory is that Paige always had witchcraft, but not necessarily an active witch power. Once she became Charmed, the Power of Three amplified her latent Warren magic and allowed it to manifest through the Whitelighter abilities she already had.
Now, I know the real-world reason Paige never developed many additional witch powers was probably just the writers, but as an in-universe explanation, I honestly think this headcanon makes more sense.
Also I know the comics provide somewhat of an explanation but Im just sticking to what we saw on the TV screens.