Have to say Jacob, thats a a load of dingo's kidneys. At least on your timeline.
Viceroy sharpening centers have been on the go for probably 3 times that, and no doubt other powered grinders were in industrial operation long before that, and before powered we had belt driven, and before that foot driven.
Nobody, especially an employer wants their staff wasting time grinding their blades by hand. Walk to the machine, switch it on, hone to readiness, and back to the job at hand.
A woodworker in a small workshop or on site would rely extensively on hand sharpening for obvious reasons, whatever the level of skill employed. Bigger shops had machines and grindstones more for grinding than honing.
Old school sharpening was normal everywhere, taught everywhere and is still used.
Things like jigs were extremely rare until the hobby craze kicked off quite recently.
The weird thing about modern sharpening is how easy and simple trad methods are totally deprecated in threads like this. It's a great loss and effectively deskills several generations.
It's just a basic, simple, useful skill. If you do it a little and often you hardly ever need to go near a grindstone.
Even weirder with the knife sharpeners - I've been solemnly informed several times that that its impossible to sharpen a knife with a steel, even though I've been doing it for 60 years with no problem at all, including serrated blades!
