Musicians and it seems guitarists in particular have this idea that there is one way to hold a pick, one way to fret, one way to…etc. For a very long time, I was no different.
The analogy I’ll use deals with bicycles. A lifelong friend of mine is a professional bike fitter and mechanic. Bicycle fit is exceedingly personal and takes into account fitness level, physical size, limitations (flexibility, range of motion etc.)
The idea being the same as good playing technique. That is - to limit the amount of unnecessary effort required. edit: This includes proper muscle recruitment. Making small muscles do large efforts doesn’t work for very long.
The main difference is that for the most part, a bicycle is fitted to the rider. The technique is left predominantly static, while the instrument (bicycle) is molded. Fit changes as you age, suffer injury or as fitness improves (or declines).
For the most part, you don’t ‘fit’ a guitar to your physical playing structure. You fit your playing to the guitar to create the most relaxed and efficient setup.
I know very little of the what and how of either of these things. But I can tell you that even getting it even 10% more ‘right’ provides improvements you cannot believe.