I find that my runs sound better when I play them using single notes.
I do often play chord melodies, fingerpick, etc., but I've been playing more single-note runs lately. One reason was because I had to find a different way to play because of pain in my hands, but it's opened up new possibilities for me musically.

Single-note melodies can sound very thin on a guitar (especially a classical guitar), so I think a lot of guitarists tend to do other things to "fill up" the sound. Playing melodies is also not that easy, so it's very tempting to fall back into doing one's "beef stew", i.e., the stuff one can do in one's sleep and superficially seems impressive. I'm judging from my own experience here.

It's amazing what one can learn from practicing. I used to pick using patterns and was very frustrated because I couldn't seem to make the leap to shifting between patterns, mixing in bass and melody runs, and so on, i.e., playing freely. Eventually, I stopped expecting that I would be able to do it. Then, gradually, it started to happen.

What really helped me was playing chord melodies and working on playing by ear. However, all the barre chords, scales and arpeggios I practiced in the past helped, too. It's all grist for the mill.

Chord melodies are good for learning to play all over the neck. Up in the upper register, one usually plays on the top four strings only. Very good for reducing pain in one's hands.

It helps a lot to just mix in some single-note lines or thin chord voicings to relax the left hand. I used to play bar after bar of full voicings using barre chords --- can't do that anymore. It doesn't really suit the kind of music I play now, anyway. Just a short bass run can be enough.