Fretted instrument intonation is a subject worthy of textbook level analysis, which has of course been done, some might say done ad nauseum. So there’s plenty of informal and formal data out there for the fascinated. Here’s a representative web page for those wishing to take a deeper dive:
https://guitargearfinder.com/guides/guitar-intonation/
It’s a funny thing… as a player of fretted instruments and the owner of an OCD set of ears, various intonation “faults” have plagued me forever. Notably, the effect of imperfect intonation in the mandolin, banjo, and ukulele is easily ignorable (for me) but on the guitar, it’s a continual, annoying, mini-problem. I manage it somewhat by making subtle tuning changes for different keys and while playing with a capo, but it never goes away entirely, even on my few very-high-quality instruments.
So... when “true temperament” guitars (they have wiggly frets to compensate for intonation faults) showed up a couple years ago, I thought, “Finally! A solution!” Found a true temperament guitar at a music store and gave it a good go. Turned out to be no bueno for me. Hard to explain why… Short on texture?? Loss of valuable overtones?? Basically it was too perfect. Not natural. Like an AI supermodel, with not even a tiny flaw to prove she’s human.
There’s a permaculture moral to this little tale, having to do with how adapting to nature tends to put controls on the demand side of the equation...