"Base salary" is a bit disingenuous way to list this. Those are often pretty low, with compensation tied to roster bonuses or signing bonuses. This is also specifically listing the leading rusher in the super bowl itself, not the team's leading rusher during the course of the year. Cam Akers had a grand total of 5 rushing attempts and 3 yards in the regular season. Sony Michel was the Rams leading rusher in 2021, with a base salary of $480,000 and a yearly compensation amount of $5.5 million. So to not include that in this figure is making a point that isn't fully telling the story.
With that said, the number of guys that ultimately played in the SB for these teams is not exactly a murder's row of players.