While I am sure this is true in a lot of cases it smacks to me of over scheduling and not being an impact player in either ec. If a kid is doing a varsity sport 6 days a week and getting good grades and having any kind of relationships with peers, mun could take maybe 3 hours a week? Is that really a deep ec or is that resume filler?
I’m sure some kids are able to do everything you’ve listed. My kids are not. My kids also happen to go to two of the most demanding prep schools in the country which I’m sure has a very large impact on this equation. Neither school is big on work life balance but both my kids thrive academically. I’m realizing that this probably has the most impact actually.