I believe most of what you said, but no college varsity player is playing only a few times a week. Even the lowest division of NCAA teams would have practice or matches 5-6 times a week in season.
Sure, but as far as the people that are going to be professional, and good enough to play for a national team, you'd already be playing in the top levels of soccer by 19. Lamine Yamal was playing for the A team in Barcelona when he was barely 16, and was a starter in Spain's eurocup win at 17. More "normal" players, likePedri and Messi, played their first minutes for Barcelona at 17.
So if you even smell a college varsity team, you are already in the slow track. It's really rare to find a star that wasn't at least in a farm team at 15. I have a friend that was already there at 10, and his ceiling was just starter in a low tier team in La Liga.
What’s intriguing to me is that several American colleges end up becoming magnets for European and South American soccer players. My midwestern mid-tier alma mater’s soccer team is 95% non-American.
So leaving aside whether 5-6 times is "a few," the bigger issue is the length of the season.
Varsity soccer season in the US is usually just four months, August-November.
Spring season (with no games) is February-April. During that season, NCAA places strict limitations on how often teams can practice: Division I and II teams are allowed only up to 8 hours per week, with just 4 of those being coach-supervised! [1]
Finally there is no organized playing for all of January, May, June and July.
So even for a player in a D1 team, they are training much, much less of the year than a 15-year-old on a farm team in Europe.
1. https://ballatyourfeet.com/when-is-college-soccer-season-fal...