Power chords are also common when guitars are played with distortion, like most of this Nirvana album.
R 5 R - the intervals are far enough apart that in this powerchord that they don’t clash harmonically.
R 3 5 R - the third is too close to the root and fifth, so the sound would be indistinct.
If you play the usual cowboy chords with a high gain tone, it turns to mush.
Of course, you can get around this with inversions to produce different voicings. I like R 5 3 with distortion to push the third up an octave, and keep it clear of it’s neighbours.
R 5 R - the intervals are far enough apart that in this powerchord that they don’t clash harmonically.
R 3 5 R - the third is too close to the root and fifth, so the sound would be indistinct.
If you play the usual cowboy chords with a high gain tone, it turns to mush.
Of course, you can get around this with inversions to produce different voicings. I like R 5 3 with distortion to push the third up an octave, and keep it clear of it’s neighbours.