What does the left thumb do then?

Almost everything else except type, it seems. I was struck last night by the total absence of its participation. Just raise it up, that's it's only role...no touch. Society wouldn't exist without it, of course, two full hands in tandem are the reason for almost everything currently built and known, yet the use of a keyboard (which requires two thumbs to build ironically) doesn't require two to use. Only one space bar after all.
Kind of coy, that. Jab hidden there somewhere. The entirety of a language at one's fingertips, and yet if you had just one finger you could say what you wanted...even if you had no voice.

Thanks