#4 Going over Reigns in major matches

The simple logic here is if two guys are competing for the top spot, the one who beats the other wins. While the two have not faced each other for some time since both are faces and on different brands, Rollins has a better record over Reigns in big matches.
Apart from the "Heist of the Century" at WrestleMania 31, Seth has defeated Reigns in singles competition at Money in the Bank 2016 for the World Title. Last year, on the RAW before Elimination Chamber, Rollins did the unthinkable by pinning both Reigns and John Cena back-to-back during the Gauntlet match.
Look who just shut down all of Tony Khan's critics! More HERE.
That was pretty much the beginning of the rise of Rollins to the top of the WWE mountain.
#3 Loved by both fans and officials

The biggest problem with Roman being the 'Golden Boy' was that he was never liked a lot by the fans as a singles Superstar. As has been the common saying, he was in many ways pushed down the throats of fans.
Rollins, on the other hand, is a massive fan-favorite. Considered one of the best pro-wrestlers in the world currently, the Universal champion knows how to entertain the crowd, and he puts on classic matches week after week. Add to that his amazing backstage support, both from Triple H and Vince McMahon, and it is clear why he is the new Golden boy.
Even if you compare the mic skills, Rollins brings out more passion and emotions than the Big Dog.