People always talk about how ballistics have improved so much 9mm is as good as .45, but doesn’t this also apply to .45?

Don’t all of the improvements of 9mm also apply to .45?

I think of it like we invented turbos and now a 4 cylinder can make as much horsepower as an old v8, but couldn’t we also just put a turbo on a v8?

No replacement for displacement type argument.

Or is this not true? Or am I missing something?