He lead the Panthers in scoring in the playoffs. While leading them to a Stanley Cup. I'd say that's performing on both sides.
Oh, now I read the rest of your post, and I regret even bothering to reply... "doesn't scream high end top line center", lol. Just a "good" player fortunate... lol. POOR MANS RYAN O'REILLY, LOL!! Can I hire you for a stand up gig for my wedding? You are funny.
Remember, I never said anything about McDavid or anyone else being a "can't win with em" player, I'm just here to disprove hilariously inaccurate takes on Barkov.
I actually think the whole premise of this thread is silly, you could technically win with a pylon on your team with the right circumstances.