even if you only use your left thumb to hit space it's still faster than using , for your leader as the thumb really only hits the space key, command(if you are

even if you only use your left thumb to hit space it's still faster than using , for your leader as the thumb really only hits the space key, command(if you are on a mac)/alt(windows) and maybe option/alt if you are on a mac. and it's natural to use the left keys after hitting space. whereas using any key on the right side of the keyboard after a leader press is awkward and slower because the , key is pressed with your middle finger. it's also a smaller target so it's harder to hit.