The NFL outside the USA and soccer in the USA are both heavily marketed novelties. Curious People with FOMO(fear of missing out) will attend annual nfl games in Europe or Brazil, and soccer games in America because they don’t want to miss out on these special and rare events. Their temporary and fickle interest in these sports never go beyond amused curiosity, there's nothing more to it. It’s like another fun activity, like going to the beach or the movie theaters for them. I guess that There might be new converts to football or soccer but most people in attendance will likely forget about the existence of these sports as soon as the games/events are over. Soccer will always rule Europe/brazil with an iron fist, and gridiron football will always be king in the USA. This will never change.
Rugby is a sport similar to football and is very popular in the UK, France, Ireland, Australia, New Zealand, South Africa. Most Rugby fans overseas look down on the NFL product and see gridiron sport as a b*stardized and inferior version of rugby. They see the nfl as a poor imitation of rugby.
Even if football grows internationally, it will never replace and overtake soccer. Let alone other sports like basketball , baseball, rugby, cricket, and hockey.
Soccer is one of the most played sport among kids in America. But it has never resulted in big grassroot interest a professional level. And playing soccer as a kid doesn’t translate to interests in the sport. Not many Americans follow the domestic league, the MLS or English Premier League. Soccer isn’t taken seriously, it’s seen as a soccer mom sport for kids in the suburbs lol. The only sports taken seriously in the US are football, basketball, and baseball . Because The best American athletes play these three sports.
Where’s the American Ronaldo or Messi yet? It’s well known that many sports fans in America are narcissistic, insular, chauvinistic, and obsessed with themselves first and foremost. They don’t care about foreign athletes and foreign sports like that. They need a local, American born and raised, relatable soccer star to even start to be interested in the sport.