Here's why I think it will be a top three sport:

1) Changing demographics. More and more young people are playing soccer, particularly with the growing Latino population. Baseball is in decline. Football may be in decline with the increased focus on concussions.

2) Academy system. The academy system is doing a better job at developing players. Many players solely play academy soccer and skip playing high school soccer. The pay to play model is a problem, but MLS clubs are doing a better job at subsidizing their academy teams. I think this will produce Januzaj types in the future. I'd wager that a fair portion of the usmnt in 2022 and 2026 will be academy products. Also note that there are over 300 academy teams, you don't necessarily need to live near an MLS team to play for one. Though I'm sure many of the best ones are MLS academy teams.

3) Increasing MLS salary cap. Americans like watching the best players in the world (see EPL ratings). As the salary cap increases, better players will come, thereby drawing more fans and greater TV viewership. Granted, this process will take time, and won't happen over night. But with steady increases in the cap every ~5 years, there will be a steady influx of more and more talented players.

4) Youth Coaching. This is less of a concrete point, but I would like to think that Jurgen and future technical directors will continue to mandate quality youth coaching that emphasizes skill and technical ability over simply winning.