The most important musical skill is reaction.
Plenty of singers can sing in tune and belt high B’s. Or float the most beautiful Baroque melismas. Plenty of pianists can conquer Liszt and play Herbie-esque changes.
But mastery is not about assertion of dominance, it’s about reacting in the moment to the musical sounds around you. Hearing what is played or sung, and changing your phrasing to match. Waiting an extra beat on a fermata because of a different echo in your performance space.
In short, the best musicians react to each other, and interact with each other, in the constant dance of keeping the music living.