The next major advancement in pencil sharpeners saw its first incarnation as early as 1910, but electric pencil sharpeners didn’t become commercially viable until the 1940’s. Their utility was obvious. Now a user could hold their hand perfectly still, insert the pencil and moments later remove it sharpened. It was practically magic.
Pencil sharpeners have come a long way since whittling with a knife and what often looked like the final answer to an earlier problem needed a few improvements of its own before it caught on, but today’s pencil sharpeners provide great utility at a reasonable price. One could say the technology has been honed to a fine point.