I would argue that a performer should be very energetic and should be able to keep the audience's attention at all time.. that is where P!nk falls compared to the other 2
Gaga slays with just her and her piano.
When she is doing the dance-pop thing, she looks more out of her element in my opinion.
I prefer to watch Gaga sing a ballad on her piano over watching Pink or Bey singing a ballad. However, Pink and Bey are better at upbeat performances with dancing
Gaga has the better performance concepts and production but if you strip that away you'll clearly see her flaws as a performer. She's a very weak dancer as well, as seen on her current tour.
If your stage presence bores people, that doesn't make you a great performer. So I'm gonna go with P!nk. It's not hard to be as consistent as she is when she does the same thing everytime, at least Beyoncé and Gaga switch it up.