I’m not a sportsfan... so maybe a Freeper who is a sportsfan could tell me:
Was this Kelce guy a world famous celebrity before Swift picked him to be her boyfriend of the month, or was he just an average sort of pro ball player mostly known just by fans of the team?
He is probably a Hall of Famer
Yes. He is probably the best at his position in the NFL. His “fame” outside of football was just taking off when he started dating Swift.