Come on man, how can you think I believe average backs equals causation?
But when teams with average backs make the SB at a rate of 3 to 1 over those with bellcows what it does tell you is that you don't need superstar running backs to be a great team.
So we should not be concerned we don't have superstar running backs.
60% of the past 10 years of Super Bowls included Tom Brady. That's skewing the discussion here. Remove him from the equation, and this becomes a very different scenario.
And even with that, you're underestimating the teams' primary backs that helped get many of these teams to the Super Bowl that weren't platoon players. These all had 1,000 yard seasons and the majority of the carries the year they went to the Super Bowl:
New York Giants - Ahmad Bradshaw
Baltimore - Ray Rice
San Francisco - Frank Gore
Seattle - Marshawn Lynch
Denver - Knowshon Moreno
Seattle (again) - Marshawn Lynch
Carolina - Jonathan Stewart*
New England - LeGarrette Blount
Atlanta - Devonta Freeman
New England - Sony Michel*
LA Rams - Todd Gurley
*Didn't have 1,000 yards, they fell just short due to games played but would have had 1,000 if they played one more game
**I didn't include CJ Anderson here because he didn't have 1,000 yards but he was the primary ball carrier and a Pro Bowler
And that's ignoring the hot hand the Bucs got out of Fournette in their playoff run this year, although the whole team was great.
That's over 50% of the Super Bowl participants in the past 10 years.