Beato and Shull put out a couple of experiment videos with string gauges. I imagine most have seen them by now.
It really drives home the impact that string gauges make on natural gain into the pickup, especially. (All related to relative mass and vibration.)
So it's certainly in the fingers. In the mind, the phrasing. It's in the strings, pickups, guitar, cable, pots, etc., etc. Hell, pick-thickness and rigidity makes a notable difference.
I also like to believe it's in this outstanding piece of modeling gear I purchased. It certainly makes me want to play more, and play better when I do.
Sure, there's no magic to the output, but it's feel and authenticity combined with outstanding effects do inspire and motivate.
In the end it's a blank canvas, brushes and palette for creativity.