Can't speak specifically to football, but as a former high school coach it's my personal opinion that kids not participate in the parent-coached leagues at all. Ever.
Girls softball for example. Before I started coaching, I went to clinics to learn new techniques. Spent time working with college hitting coaches to make sure the information I passed along was right. Bought training videos with my own money to understand the girls game (because it's different from baseball) and get new drills I could teach them for fielding, hitting and throwing.
Horn tooting time: I inherited a team that had won something like five games total over the past three seasons and had no expectations. We won 16 games our first year and made the playoffs for the first time in school history my second. I had five players make all state over three years on a program that had NEVER had an all state player before. Sent three girls on to play college ball.
The biggest problem I had as a coach? Idiot, moron Dixie Youth coaches. The first few practices of the first season, I started every girl working basic drills. Simple things that they should know about fielding grounders, running bases, batting stance, catching and throwing. These assclowns stood at the fences coaching "their" girls and undermining everything I tried to do. Thank god I had a strong AD who backed me when I banned them from practice. They then took up residence on the hill behind the practice field shouting instruction. Banned them from there. Spent that entire season dealing with "Well, Coach Mark said I can't hold a bat the way you say, I've got to do it like this" and every time they were wrong.
Had a meeting with these bucktards after the season. Me and the AD and some parents. Asked them to let us coach the girls without their interference, that the results spoke for themselves. For the first time in forever, we were winning. Instead, they got angry and claimed we were trying to steal their success, that these girls were coming to high school ball "ready made players" and all we were doing was screwing them up by contradicting their methods. I asked them where those results were the year before, the year before, the year before. They said it was just "a more talented crop of girls." Idiots.
Before the next season I held tryouts and said flat out I would not take any girl who intended to play Dixie Youth. I provided them with references to play travel ball (which wasn't much better, but it wasn't local and the competition was better).
The Dixie coaches wanted me fired. Again my AD backed me. And we won. We won a lot. We started hitting, the fielding improved, we learned how to be tough. Learned how to pitch, not just fling the ball up there, but actually pitch to spots, set up hitters, work counts. Made the playoffs the next three seasons, but never could get out of the semis. Always ran into that one team with a bull of a pitcher that we just couldn't string together enough hits on.
Dixie coaches raising hell. Stole all their good players. Pretending like it was our coaching that was helping, when those girls got there knowing how to play good ball. Bull. I spent more time undoing their lousy coaching than anything.
After four years of that nonsense, my AD left, we got a new principal and I got another job.
The Dixie coaches got right back in the mix with the new guy. One started "helping" as an unpaid assistant.
Within two years they were back to winning a handful of games a year and getting blown out on a regular basis. Went to the playoffs the year after I left and haven't been back since (14 years or more). They can't hit, can't field, can't pitch. But that Dixie Youth program is still going strong.
I know a lot of you parents put in your free time to work with these kids. And I admire that. But you're not a coach. FWIW, a lot of high school coaches aren't either. I let my oldest daughter play in that Dixie program and later play for a parent who took over the high school team when they let the history teacher go in the middle of the year. I regret it. She learned nothing and was treated badly.