Someone believing those teams are the favorites is not the same as them saying nobody else is "capable". Like if you had to bet all your money on those four teams or the field to win the Super Bowl, I'm guessing the vast majority are choosing those four teams.
To me, the Ravens are absolutely in that group of favorites too, and I could see the Packers maybe making a run as well. Can't say I have a lot confidence in anyone after that, but there are a few that are maybe close. The Broncos, Seahawks, and Commanders are all in the "maybe if they get hot, but probably not quite there yet" category for me. I should probably have more faith in the Vikings than I do. I thought the Rams were getting healthy at the right time and turning a corner, and maybe if they get in I won't completely dismiss their chances, but they have not looked impressive the past four weeks. The Bucs appear to have the ability to beat, or lose to, anyone.
Gun to my head, I'm thinking Bills-Eagles for the Super Bowl. Hopefully the latter changes because I hate the Eagles, but they look damn good and the NFC as a whole doesn't look spectacular to me. I don't trust the Lions still.