Vision - Yellow Mind Stone (Scepter)
Scarlet Witch - Yellow Mind Stone (Scepter)
Capt. Marvel - Blue Space Stone (Tesseract)
One would think Vision and Scarlet Witch would be at least on par with Capt. Marvel. Scarlet Witch held off Thanos and destroyed the Mind Stone.
She might be as powerful. It's all in what powers are given and how they're used. Let's face it, Scarlet Witch pretty much took out those giant wheel things Thanos' army was using with a wave of her hand. And Vision was able to wield Mjolnir.
shareVision holding Mjolnir was not based on power. It was either because he's an android and thus not alive (as has happened in the comics many times) or he was worthy enough to lift it. They talk about this at the end of Age of Ultron.
As for this thread, I don't see Carol as massively more powerful than, say, Scarlet Witch or Vision. I'm also not sure she's all that more powerful than Malekith when he had the Reality Stone or Ronan when he had the Power Stone. They all had different powers but were pretty damn powerful.
But wouldn't part of what made him worthy be partly because his being is worthy? And isn't his being part (IIRC) Stark, part Banner, part Mind Stone, part Jarvis and even part Thors' lightning? He's a gestalt being but part of that gestalt is the stone.
Yes, it's a stretch but not too far of one.
Worthiness and power are two different things. In the comics, Captain America has picked it up but the Juggernaut failed. The Juggernaut is a million times more powerful than Cap.
Also, you forget that androids can pick up Thor's hammer. In the comics, Ultron and Airwalker picked it up since they are robots. They just didn't get the power of Thor when they did it.