To me is not so much that, it's more to the point
@SixPapaCharlie raises in his own video. There's a pivotal difference between a pre-briefed formation flight, and a gaggle of amateurs being told to in-place 90 left towards the same point, in what becomes an unbriefed Tac Wall formation, and dissimilar no less. That's considerably more hazardous than the 100 ship or whatever pre-briefed formation, by orders of magnitude.
You can see airplanes stacked above and below each other's blind spots in that video (many which I'm sure the author never saw until he downloaded the video), and no one is talking to one another (not with any sense of purpose anyways) on air-to-air. All it would have taken is for someone to change stacks between a hi-lo wing combo and smack, confirmed kill for Oshkosh.
Even as a career tac-trainer pilot with more fingertip time than some people have total time on here, I would have absolutely RTB'd early from that mess. No way I entrust my life to the peanut gallery like that.
@SixPapaCharlie is right, the priorities for arrival got flipped on this one. You get the amateur conga line in first, and in trail at that (the only formation they can't eff up, though they still do), not the pre-briefed and self-deconflicting formation flights. I understand that from an event value, getting the showy arrivals is of higher importance to the organizers. Them's the breaks.
The RV site is blowing up with threads like this one (some RV driver loitered for 5 HOURS!!) regarding this buffoonery, but the unicorn IMC pirate boogeyman is somehow blasphemy?
You’ve hit upon the key parts but missed a few.
The aircraft at different altitudes going the same direction, are doing it wrong except for the higher speed aircraft, which are stacked high.
The aircraft CROSSING are departures and go-arounds off of 27. They’re stacked LOWER than the inbounds and are climb restricted.
You have to read the NOTAM and understand where everyone is going. The bigger problem the controllers created was sending people to the smaller lake. Too many airplanes to even mention it, they should have been saying to hold at Rush Lake.
As for the mass arrivals, they’re efficient and they’re usually two days before this day. With weather, they were delayed into the busy “amateur” arrival day, and three days worth of aircraft descended on the field in a single day.
They’re considered “controlled” for a loose version of the term, from takeoff until landing. They’re given a specific departure clearance from their staging airport that is usually a direct shot up from the south to land in simultaneous parallel landings on the 36s.
Once launched, they’re coming, and they’re going to maximize the use of four landing zones/two runways for 30-60 minutes. Those runways become unusable for the controllers at FISK.
That means you have two landing surfaces/one runway (9/27) for all of the VFR aircraft circling the two lakes. There’s no physical way for that many aircraft to land on the remaining surfaces. They couldn’t have landed all of those aircraft on all six surfaces, even if they had them, if you ask me.
You hit the real answer in your post, too... if you see three days worth of traffic backed up at the lakes and you’ve gone around the lap 20+ times, you’re better off landing elsewhere and waiting for the insanity to subside. You can do laps if you like, but the FAA wants to give NO indication that you’ve passed FISK and are now under their control.
You’re VFR in a gaggle of airplanes who can’t seem to hold an altitude or airspeed with any sort of precision... you can stay and play tag with them, or just land and wait it out.
The mass arrivals really have nothing to do with it, other than occupying four landing surfaces when they arrive. Two disabled aircraft on any runway will have the exact same traffic effect.
And that happened too, as seen in the nose gear collapse/porpoise video. Closed 9/27 instantly for quite some time. Every time an incident happens, you lose two landing surfaces.
That system and airspace were saturated by three days worth of arrivals attempting to arrive at the same time, that’s really all it was.
It was dead calm on the radio and the controllers sounded downright bored by noon the next day after those who overnighted elsewhere finished arriving.