I worked with guys who could hand grind a drill bit perfectly every time.
I could never do that, so they were all very dear friends!
The problem with a drill sharpening jig is it doesn't really grind the relief
from the cutting edge.
Bits sharpened in a jig will drill but the cutting edge will often have zero or
even negative relief. They don't cut well and burn up quickly.
This isn't a plug for Drill Doctor, but it explains it better than I can.