I bring my truth through experience as a parent, coach. Together, coach & parents can make youth soccer great again. It is from my lens as father, so take with a grain of salt and your favorite shot of tequila, on me. I knew a coach that had the A Team and B Team. He had a healthy way of coaching for the most part and his training was top notch. He basically had the same idea as you. If done right, with respect and transparency, then coach, parents and players on both A Team and B team can make it a win, win, win for all. It's like having the varsity coach who is also coaching JV or working together to give those on the JV a chance to win a spot over one of the lazy varsity players or underperforming players. It happens all the time and a good coach will know this to be true. Good old competition is the key for the future of sport, that's based on merit, hard work and ganas with results. It's the only way to coach. Mom and dad go sit in the stands and watch, cheer and ENCOURAGE your child to work hard and most importantly, have fun. On paper this is the best, moo. Let's be honest parents, kids slack off or some think mommy will just pay extra to make sure her play time is not taken away from not working hard. For me personally, it's A team or I find another A Team down the street to seek my revenge. No B Team for crush unless I'm on JV. I was never on JV. Freshman basketball and then the call up in 10th grade varsity. I saw firsthand I was not D1, D2 or D3 for that matter. I was NAIA because that was the truth. I love this stuff.This comment from Crush is so true. If I had a dime for every time "A" team parents crapped on "B" team kids I could retire. Given the quite mediocre level of most top teams, it's comical. Especially in the top national leagues. Parents aren't exactly excited about your kid taking playing time away from Johnny's Division 1 College highlight reel.
As to the difference between A and B teams, generally speaking the first team should present a higher paced, technically advanced, physically and mentally challenging training environment to develop their game. In a quality club, the age group presents opportunities for select kids from the second teams to train and/or guest play with the first team. This is often promised, yet seldomly delivered.
To be honest, if your kid isn't watching/studying the game, and putting in work on their own time to improve their skills, then the whole narrative of expecting to play on the "A" team is a moot point. Expecting coaches and teams to develop your players is understandable, but from my experience, even in top national teams, half or more of the kids don't even watch the sport or put in time on their own training their skills and playing the game. So what's the point? Just setting yourself up for disappointment and empty pockets.
The absolute best teams I have developed have been second teams with a great supportive parent group, kids who love to play with each other, and push each other as a group regardless of skill level. It really depends on the situation and the quality of the group/coach/team.