Fretted instruments, especially electric guitars, are usually not strictly equal temperament and are made to have just intonation in at least some combinations of notes because equal temperament sounds bad with distortion.
There exist equal temperament guitars, but they're usually custom built:
In any case most people don't mind such small differences, especially that guitars aren't terribly precise to begin with - a player can easily get 10 cents of a semitone on each individual string when playing a power chord with distortion, bringing the whole thing to just intonation.
There exist equal temperament guitars, but they're usually custom built:
https://guitargearfinder.com/faq/true-temperament-frets/
In any case most people don't mind such small differences, especially that guitars aren't terribly precise to begin with - a player can easily get 10 cents of a semitone on each individual string when playing a power chord with distortion, bringing the whole thing to just intonation.