@Kardamom, I think you’re right, the electric ones don’t really work better. They often get going crooked and give you an off-center point that is half wood, and they can chew your lovely pencil down to half height in a couple of seconds. When they do sharpen to a needle point, it is much more apt to break than an adequately sharp hand-cranked point. I love a sharp pencil and won’t use a dull one, but one that snaps off instantly is of no use at all.
To me the main virtue of an electric model is that it can be installed in a cubicle environment or other setting where there is no place to put a wall-mounted mechanical one. (Forget the ones that are supposed to mount by suction instead of screws.) Somehow throughout my cubicle-bound career I always managed to have a pencil sharpener in my own cube. Given that much of my work was done with pencil, I’d have been a very highly paid graphite grinder for the hours I’d have had to spend twisting pencils through the tiny single-blade devices, which anyway always made such a short point that the pencil had to be sharpened again right away. God bless electric pencil sharpeners, say I, but I’ll keep my pocket knife handy all the same.
(We do have a mechanical one installed in our house. It’s been there for 40 years.)