Not sure how you watched that Cup run and came to that conclusion. Elite talent is required, but depth is what got us into the Final.
I mean, timely depth scored some goals, but it's kind of a misnomer to say depth is what got us to the final. Do we make it without those timely short handed goals? Or the random ceci and foegele goals? Possible we don't or simiarly possible their replacement scores.
I'd pretty comfortably bet that in an alternate universe, if you take away a few of the depth goals we have a better chance of making the finals, than keeping the depth goals and trading out half of McDavids points. I'd much rather dump McLeods 5 points for some other random NHLer than dump a 43 point playoff player for a mixed bag of top 6 elite talent.
IMO there's a near zero % chance we make the finals if you exchange Barkov for McDavid. I just don't see it. Is it chapped that McDrai was pointless in game 7? Hell yeah, basically win the game if they find ways through. But given McDavid single handedly won us two games to even get there I'm not sure it's realistic to put any blame on him. Likewise with Drai being a corpse the last 10 games of the season.