Youngest son never played rec ball past 6U pitching machine ball. Started kid pitch travel at 6U (yes part of that group). The first travel team had 9 of 11 started varsity as a freshman with 8 playing college in some sport and 1 being drafted right out of HS. He changed teams at 9U to another local team and that group has 7 playing college with 2 being P5 and 3 others D1 the same kid as on other team drafted out of HS. 11 of the 12 started varsity as freshmen. Ranked in top 10 nationally every year they were together until 14 with all the kids except 2 being from 30 minutes of each other in NE Tennessee.
Middle son's local travel team had all 11 start varsity as freshman or sophomores. 7 played college with 2 drafted. 1 pitching in MLB and 1 pitching in AAA. Ranked in top 10 for 4 years with everyone being from 15 minutes of each other in NE Tennessee.
I would disagree to some extent that what happens before big field is irrelevant. If you start playing travel young enough on a high level team you learn mechanics and build a resume. You also are not overwhelmed when you hit the big field because you have seen the high caliber pitching/hitting. You will not be scared of anyone you face because you have seen it. I look at most of these kids and they were in the recruiting process as incoming freshmen in high school.