> it was rare that I had a scheduled sports event on a Friday or Saturday evening
When I grew up in the South, football & basketball games were Friday & Saturday nights. Apparently this was common[1].
1 - https://en.wikipedia.org/wiki/Friday_Night_Lights_(TV_series...
High school sports, yes Friday night is the standard time I think across the USA. Has been as long as I can remember, or at least as long as schools had outdoor lighting on the fields.
Wednesday was Peewee/little kid sports, Thursday evening was Jr High sports games, Friday evening was High School sports games, and Saturday was college sports games.
Where I grew up (and live now) - DC metro - those games are often Friday, but it's not that common for families without high school kids to attend. And by the time the kids are in high school (or even middle school), the parents just drop them and come home. But yeah, unsurprising that these are bigger social events south and mid-west.