The context of the discussion is one where the difference between SoA and AoS is significant. It’s not always true in general that your program won’t be as efficient as possible, but it’s true in the context we’re discussing, where you have a lot of things (entities or whatever) and you’re iterating through them, which is what is being discussed.

I was writing a direct answer to the question of “how can it be true that C++ isn’t built for modern machines even though modern games with good performance on modern machines use C++”. I think the answer is entirely correct in context.