> You can do advanced maneuvers without getting so close to another plane in some weird attempt at simulating a scenario that will never happen.

That is likely true. However, it is a heck of a demonstration of pilot skill. The Blue Angels somewhat regularly post in-cockpit views of their airshow practice and it is wild how tight a formation they fly; I really recommend seeking out some of those videos, it is totally worth it. Well, for me at least :). It is not unheard of (but not common) for them to inadvertently make contact, since they fly like 18 inches apart, but given they have nearly identical vectors it does not often result in a crash.