Watching this year's postseason makes me think that the answer to this question is that I want to have a dynamic skill player somewhere on my offense without a preference for what position that player plays. Obviously the trenches are an important area, but to me the offensive and defensive lines and pass rush are largely products of group play.
I think that it's the piece that a lot of the lower end and a lot of the losing playoff teams don't have that some of the better playoff teams do. Indianapolis Pittsburgh and the Rams come to mind as playoff teams that have good offenses in good quarterbacks and good offensive players, But they don't have a really really dynamic physical skill player.
Like Cleveland has Nick Chubb, Buffalo has Diggs, Green Bay has Adams, and Kansas City and New Orleans are both teams that have two of those with kamara and Thomas in New Orleans and Kelce and Hill in Kansas City.