Another great post boxer, I think the current situation is impacted by three main paradigms:
1. Technology (as you say)
Won't spend much time on tech, as I basically agree with your assertions. Although, I would place slightly less emphasis on tech, as a reason for the current softening market.
I feel as though there is a natural 25-35 year cycle for supercar desirability. The poster on the teenage boy/girl's wall becomes the object of desire and nostalgia once one has enough cash to buy, etc. In between then, many classics go through periods where they are cheap and not really valued. What is interesting is that this is still a very recent phenomenon; supercars haven't existing for very long in the grand scheme of things. Does somebody in their mid-40's today remember what supercar came before the Countach, Testarossa or whatever poster was on their bedroom wall (remember "Justification for Higher Education")? Moreover, do they care? Will McLaren F1's still be valuable when the high net worth population doesn't even know what it is? I suppose that has ramifications for our heirs, not us.
Damn, a lot of exotic and sports cars were pumped out in the last decade. Rather than placing blame, I prefer to think of it as just a reality and natural consequence of any market bubble. But umpteen special editions of basically the same car (maybe Lambo and Porsche started it, but Mac took it to another level). Emerging markets like China and high stock markets providing the fuel for the frenzy, of course. But as the cliche goes, a rising tide floats all boats and vice versa. So even Enzo prices will retreat. Still, I wonder if the soft supercar market is a harbinger. I remember seeing F40s at CAD $400K asking, during the financial crisis. I passed up a Carrera GT for CAD $325K. Doh!
The holy trinity are unique in that they are truly hybrids, not only in powertrain design but they mix, or span, the two underlying eras of the automobile. Before EVs and after EVs. Does that make them more, or less relevant in the long term? I don't know. I could make an argument either way. But the P1's battery replacement costs are a problem, I agree.