“...the Blue Angels did a show at Westover ... they were doing what I assume were practice maneuvers in the area and they were flying full speed (or so it seemed) ...
Not even close.
The F/A-18 has a max speed close to twice the speed of sound. Military aircraft are barred by law and regulation from exceeding the speed of sound within the boundaries of the lower 48 states (except for special-use restricted areas).
Flying above the speed of sound has little value from a military point of view.
In an air show, a machine breaking the sound barrier goes by so fast the spectators cannot really see anything. Poor public relations. Quite apart from the broken windows the shockwave causes.
The only way to fly that fast is by using the afterburners, and the dash cannot last long. Fuel flow at these power setting is so high a fighter-size aircraft runs out of gas in less than five minutes. There are a couple exceptions (F-22, B-1B).
An aircraft running on afterburners causes a signature in the infrared spectrum the size of a searchlight on a dark night. Impossible to hide from IR search systems or heat-seeking missiles.
60 years ago afterburners afforded a manned aircraft the chance to run away from some threats. Missile technology has advanced since then: for over a generation, it has not been possible for a manned aircraft to outrun or out-turn a pursuing missile.
Mechanical kamikazes!