It will depend on the switch, but personally on cherry blues and browns I can type while looking away from the keyboard (or screen) with basically 0 typos. On cheap keyboards either I type harder (and slower) on purpose to be sure or I just miss keystrokes randomly.

I can get by with a rubber dome keyboard by if I just write comments like this one, or light office work, where I see immediately what I type, but certain tasks don't have visual feedback (or you just look elsewhere).

In my case, using Vim in normal mode (command chains aren't usually seen until they execute), taking notes off meetings/presentations, doing translation work, adapting code snippets from elsewhere, and refactoring code benefit greatly from touch typing.