I could never be right. Different strings might require an intonation adjustment. Different temperatures, humidity. That is why they are adjustable, because they need to be adjusted. Obviously depends on your sensitivity to intonation errors. No matter what, the intonation is never perfect, but can get close enough for my ears. I normally do not adjust my guitar for every string change, but I use the same strings. If I bought a different brand or size of strings, the intonation would need to be adjusted.
Acoustic guitars are often fixed intonation. For the most part you are not playing way up there on the fret board. If you measured with an accurate tuner you would find inaccuracies probably.