> is so elegant it’s still being used today
I think it's the "so elegant" part that's wrong. It's not still being used today because it's so elegant. It's still being used today because the old helicopters haven't replaced it.
if it was less elegant from a function/cost perspective, it would have been replaced a long time ago.
I think elegance has to do with the technology of the time. Some clever design that is cheaper/better than you would otherwise think possible given the era. There are probably many elegant aspects to Roman aqueduct engineering, but they would still get replaced with modern materials during a retrofit.