I think you underestimate how often American football fans watch their favorite team's games though. I definitely agree that the random name thrown in with all the legitimately well-known celebrities seemed a bit odd though, I was just pointing out that there were probably a number of individuals you could have chosen that would have made much better comparisons, and that the numbers point toward Tom Brady being a much more famous individual if you use viewership numbers just on his games alone, not counting his external media coverage in addition to his actual play.
They're obviously both famous, but I'd say that it's within their particular audiences only. My overall point was that it was a poor comparison when you're trying to compare someone who is on a platform viewed across the entire globe to someone who is generally only televised in North America. Using these particular individuals where the former has the greater availability for viewing, the latter still ends up most likely being more "famous" if you were to quantify fame with a number of some sort. Most of this has to do with the density of their fans within certain areas as well as advertising and media attention (news footage, ESPN, etc compared to Youtube and social media primarily) and makes for a difficult comparison. If Tom Brady were to casually walk down the street in the US he'd probably be swarmed by fans who know who he is and what he looks like, while if Pewdiepie did the same it's highly unlikely to occur because of this, even if a comparable amount of people globally know who they both are.