Here is my question: why is it faster to sharpen a hollow ground blade?
Don't you still have to move the blade over the stone the same number of times? Clearly, there is less metal to remove, but the energy required is all about the number of strokes or the time devoted to sharpening.
I can't understand how the effort is really any different when moving 1/8" or even 1/4" of steel over the stones versus moving two 1/16" ridges with a hollow ground space between them over the stones. I hope my description makes sense.
Another way of picturing the blade to be sharpened is to think of it as one relatively thick line of steel versus two thin parallel lines of steel with a narrow, empty space between them. Would the two narrow lines get sharp faster? If so, why is that so?

If I am wrong, I hope you can help me understand what I am missing.

I can understand that less steel would offer less resistance when slicing wood, and there may be some small reduction in wear on the stones, but my question is about the ease of sharpening. Thanks for your thoughts.

Regards from Philadelphia,
Ron