Let's not pretend emacs/vim are perfect; there are certainly situations where they slow down. I certainly have files where the syntax highlighting isn't so speedy or where it's temporarily broken.

I'm just trying to point out that attempting to compare applications from a certain period in computer history to modern applications is doomed to fail.

While I certainly believe optimisation work would help some modern editors, it would be silly to attempt to blame that all on optimisation work instead of recognising that the world is different now.