One of the differences is in Europe (and SA) is the club system. They are actual clubs--with their own fields, clubhouse, restaurant, etc. This like a country club, but not as fancy. Many teams at all levels of competition. This was true of bigger teams in Europe as well, though in the past 30 years, most of the top level teams have been split off from the main organization to protect the finances (when a pro team went bankrupt, that took the entire club with them). An example: Bayer Leverkusen was once the factory club for Bayer Chemicals. There are hundreds and thousands of these clubs, so there is plenty of competition at the local level. We have some of this in the US--in my hometown of Warminster, PA, there's VE (Vereiningung Erzegeberge) which has been doing this for I think a century or more--and have made the first round proper of the US Open Cup a couple of times. United German Hungarians are another in the Philly area. The social activities of the clubs also support the sporting side. These clubs in Europe also sponsor a whole lot of other sports, some of which are surprising. Bayern used to have a chess team, and former Bundesliga team Unterhaching had a bobsled division. Some of these clubs have done well at other sports. Bayern and Real Madrid have top basketball teams, and Bayer Leverkusen was quite famous for its Olympic track and field athletes well before they ever had a Bundesliga team. Being local, there's not as much travel needed.
We do need our MLS sides to continue to develop an academy system, but that's only 30 or so around the country. There are gaps.