America will win one of the next four world cups. It's inevitable. Huge population size, unparalleled sporting culture, a massive sports/training infrastructure, and the growing popularity of the sport. An entire generation of kids will go through school realising it's a a better route to take than conventional American sports, as even if you don't "make it" you can still make a living in a decent league anywhere in the world. That and you don't need to be over 6'5" or be willing to get concussed every week like in basketball or US football respectively.
It's not going to happen. American players simply do not and will not have enough experience from the toughest games in order to make a proper run for the cup. USA also lacks a foundations like Europe where mane countries have such an advantage considering how popular the sport is. Even small countries like Belgium are way ahead in this regard. In European countries you don't only have one proper league with big teams that compete in the Champions League but many divisions. Every town and city has its own team.
Look at Germany for example :
I: Bundesliga (18 teams with heavy hitters like Dormund and Bayern)
II: 2. Bundesliga (18 teams)
III: 3. Liga (20 teams)
IV: Regionalliga (with four divisions constituting a total of 88 teams)
V: State leagues (too many teams)
VI: Lower state leagues (EVEN MOAR TEAMS)
Below the state association league system you have another 67 divisions and close to 1000 teams.
VII: Kreisliga
VIII: Kreisklasse A
IX : Kreisklasse B
X : Kreisklasse C
XI : Kreisklasse D'
That is not to say MLS is garbage, it is a competitive league with entertaining matches. Just like the Swedish Allsvenskan is an excellent league with proper talent and great atmosphere. People should be happy to support their local teams regardless how many proper stars play in them.