Why does G string (the third one) go out of tune constantly on

Why would the two B strings, supposed to be in unison, be the strings that go out of tune the most often on a 12 string guitar? - Quora

Is it bad to change your guitar tunings constantly? For example, I am constantly changing from standard to DADGAD and ECDGAD. Does this shorten the life of strings? - Quora

Standard guitar tuning is in intervals of perfect fourths except for the B string, which is a major third above the G string. Why is standard guitar tuning not all in fourths?

Why do so many acoustic guitars have 3x3 tuners while so many electric guitars have in-line tuners? - Quora

Why do guitar strings sometimes go up in pitch when they go out of tune? - Quora

Why do so many acoustic guitars have 3x3 tuners while so many electric guitars have in-line tuners? - Quora

When a particular guitar string constantly goes out of tune (flat), but the intonation on the guitar is good otherwise, what might it indicate? - Quora

Why does the G string on a guitar always go out of tune the fastest? - Quora

When a particular guitar string constantly goes out of tune (flat), but the intonation on the guitar is good otherwise, what might it indicate? - Quora

Why does the G string on a guitar always go out of tune the fastest? - Quora

Why does the G-string on a standard guitar set at 440 tuning sound out of tune? - Quora

Why is the 'G' string the hardest to keep in tune? - Quora

Is it normal for new guitar strings to go out of tune? - Quora

When a particular guitar string constantly goes out of tune (flat), but the intonation on the guitar is good otherwise, what might it indicate? - Quora