I have to emphasize the sentence you ended your comment with. Anybody who has worked in volume production has heard this phrase too many times to count.
People who never learned the difference between QC and QA never seem to understand this phrase either. Doesn't mean they are dumb, but does mean they don't even understand the scope of what they don't know.
Another common misunderstanding is the dynamics of the learning curve. Costs of high volume production drop precipitously (and quality typically increases proportionally as well) but incrementally as volume goes up. A common misunderstanding is that that means you work incrementally to get better. But that is true for systems set up from the start as high volume systems. Tesla the company has been at it for almost 15 years (Musk has been there for 13 of them) and still appears to be in low volume manufacturing mode.
It's not super surprising when you consider that Space X makes small volume, bespoke hardware. A big backend system is still a one-off even if you run huge volume through it. Cars, phones, etc are a completely different game.