> that misses the point that Apple literally can't buy enough memory at any price.
They can't buy enough today. I think I already explained this as well as I can in my second paragraph above. You seem to not be appreciating that every decision in this business has a 3.5+ year latency. And 3.5 years ago when Apple made the decisions they're living with now, Micron was selling their furniture (euphemistically speaking). Sinking billions into building RAM fabs would not only have gotten you laughed out of the boardroom, Apple shareholders would have rioted (for all the logical reasons I laid out in my prior two posts). The only scenario where the prudently balanced decision Apple made to not vertically integrate RAM manufacturing looks bad is the very unlikely scenario that actually happened this one time - but that 'bad look' is only temporary because the situation will probably look different 12 months from now (which is less than a third-of-a-fab-decision away)).
Back when I first became a strategist for a public F500 tech company whose products you probably use often, a very wise man took me to dinner and counseled me to never post mortem my decisions on the outcomes, but only on the decision process. In other words, knowing what I knew when I made the decision, did I choose the option most statistically likely to get the desired result - regardless if it worked or failed that time? In highly uncertain games, some bets don't pay off. In my work, if 60% of my decisions came out positively, I'd have been the greatest of all time (they weren't that quite that high). If strategists don't think this way we end up leading our companies to doom by "chasing black swans" (aka unlikely outlier outcomes).
> memory manufacturers leave demand unmet
That's not their plan or desire - it's just the inevitable result of trying to predict both future demand and future capacities of unbuilt fabs on new nodes (every new node is an adventure). Both are rough estimates with bell-curve probabilities and wide error bars. You might imagine the Chief RAM Strategist drags the center of the bell curve so the big bump in the middle is right over their best guess of what the fab yields and market demand will actually be three years from now - perfectly slicing the odds in the probabilistic middle. But they don't. Instead, being a smart, experienced strategist, they slide the bell curve a little bit to the low-side - because very profitably selling everything you can possibly make and regretting the 5 or 10% of demand you left unmet is a far, FAR better (and more survivable) problem to have than sitting on 5 or 10% unsold excess capacity from expensive fab space you paid to build but can't monetize. That extra capacity will often force you to take lower margins on ALL your capacity to ensure you sell through the extra 10%. This is how you speed run becoming an ex-strategist, sometimes of an ex-company.
In short, being wrong on the low side is the best kind of wrong you can be. But being wrong on the high side is the worst kind of wrong, and it's not linear. Every extra percent you go over costs significantly more than the last. If they do their job perfectly, it looks to consumers like "manufacturers leave demand unmet." If they do their job less than perfectly but pretty well, it looks like "RAM's too damn expensive and the idiots created a shortage - what were those morons thinking?" If they do their job catastrophically it looks to consumers like "Woohoo, RAMs dirt cheap. Look at me! I've got so many sticks I'm bathing in them like Scrooge McDuck!"