That was the thinking at the outset of the Vietnam war, and in the early years of the war the Navy air combat kill ratio was 3.7:1. With the advent of USN Fighter Weapons School (AKA Top Gun), which taught advanced air combat maneuvering skills, the kill ratio went up to 13:1 before the end of the war.
ACM is still imporant for fighter aircraft. ISTR that in the 1990 competition between the YF-22 and YF-23, the YF-22 was less stealthy but was ultimately selected for production because of its superior ACM agility.
They may not have them, but the lack of a canopy frame wouldn’t be the reason. If they really wanted mirrors, they’d find a way to attach them, either gluing/screwing them directly to the canopy or installing a metal hoop or stanchion on which to mount them.
They’ve been saying that forever, and as JRDelirious noted the F-4 was originally not equipped with a gun at all, so firm was the conviction that most engagements would be at BVR with radar guided missiles and the AIM-9 Sidewinder would be enough for any rare dogfight-ish situations. This of course proved not to be the case, and the F-4 was quickly fitted with a 20mm Vulcan and emphasis was placed back on teaching basic fighter manuevering.
During Desert Storm in 1991, in spite of all of the advances in technology, not the least of which was positive control of intercepts by E-3 AWACS aircraft which could track everything in their airspace and removed the need to make a positive visual ID of the target before engaging with BVR missiles (in Vietnam the usual method was for one plane to make a high speed pass on full afterburners to confirm the target as hostile to his wingman), a substantial number of engagements involved dogfighting and kills made with AIM-9s. In perhaps the most interesting air-to-air engagement of the war, an unarmed EF-111 made a kill against an Iraqi Mirage F-1:
I believe the pilot seat of the F-16 also sits higher in the cockpit than is usual, specifically to provide for better fields of vision out of that big plastic bubble of a cockpit - it was always meant to be an all-up-in-your-shit close-range dogfighter plane, so anything to facilitate rubbernecking and keeping one’s target in view at all times.
While not technically a commercial jet, the Gulfstream G-IV has a small convex mirror mounted at each cockpit side window. Their purpose is to allow the crew to verify the movement of the spoilers during a preflight check, as there is no cockpit indication of the spoiler position. While I suppose one could see an aircraft approaching from behind with these tiny convex mirrors, you would have to be staring at the mirror at just the right time to notice anything at all. Even then, good luck doing anything about it…
Well the one in the goggle reflection is an IDS Tornado (recognizable by its fuckhueg vertical stab) so one can probably assume the selfie-taking pilot is flying one too.
Back in Gulf War One, a British Tornado was shot down after failing to release its bombs on a low level strike on an airfield. The pilot and weapons dude ejected, were captured, and eventually released. In the interviews with the pilots afterwards, I distinctly remember one of them saying that, after they were hit, they saw the flames crawling up the aircraft in the rear view mirrors attached to the canopy support ( which would be the mirrors in that pic) , at that point the decided to exit stage upwards. So useful for spotting both enemy aircraft, and imminent unplanned energetic disassembly of the aircraft.