I was surprised about vi going in, though, I didn't know it was in System V.
The reason I use ed is that I don't want to lose what's on the screen.
I think the Macintosh proves that everyone can have a bitmapped display.
But no, I don't generally have trouble with spelling mistakes.
The point is that you want to have a system that is responsive.
A bomb is blown up only onceโbut one bot can become many, and quickly get out of control.