E/G# is a phenomenal chord. It’s the first inversion of E major and most commonly used as a 1/3 chord in the key of E major. It leads really nicely to the 4 chord(A).
Learning the basic E/G# means you can also play A/C# and B/D#.
Both very nice chords in the key of E.
With a slight modification to the shape you can also play Maj6 chords like A6 and B6 along with non-diatonic chords in E like G6(b3), C6(b6), and D6(b7).
E/G# can also be used as the non-diatonic 3 major chord in the key of C and Am. A progression like Am-E/G#-G6…. really brings out the beauty of this chord on guitar.
For the full tutorial checkout E/G# Deep Dive
https://vimeo.com/1061197453/5f4c2c32f9