> If I can watch an NFL replay in 4k a few seconds after the ball is snapped, why not record (and overwrite) all flights that take off and land at every airport?

An NFL game has a ton of cameras, a ton of camera operators, those fancy cameras on wire things, an onsite editing crew, and an audience.

To get good recordings, you'd need to invest a lot of time and money, and very few of the recordings would ever be watched. Doesn't seem worth the investment given third party recording seem to turn up quite often and video isn't terribly necessary for the investigation.