Is it just me, or is the sight of a tuning device hanging off the peg head a sign of someone who is not that musically adept? Sounds harsh, but in the past you learnt to tune from a source note and tuned all strings relative to that, such as from a piano keyboard, a portable pitch pipe or in my case a g harmonica. Rather than relying on a machine, you developed more of a musical ear, and simultaneously learnt to play the harmonica and also unravel the mysteries of scales, and learn where the different notes are on the fingerboard, etc.

Tuners only tell you if the open string is tuned up to the correct pitch, but you usually need to fine tune using fretted notes at say the fifth and tenth frets to check it corresponds with next and next but one string, since intonation often goes out as you move up the fingerboard (even on high end instruments) - most of the time you will be sounding notes part way up the neck, and it’s more important that those are up to pitch rather than the occasionally used open strings to my mind. These days though, I tend to do both, using a tuner for initial tuning then relative tuning for a best fit intonation.