Twp points to complement the other answers:
 

1. Playing one note at a time (whether in scales, arpeggios, melodies, etc.) helps you fine-tune your sound/tone.
   
    
2. Especially when you are new to the guitar, practicing various scales can help strengthen your fretting hand and will allow you to move between various chord shapes/voicings more easily.

Two points to complement the other answers:

1. Playing one note at a time, whether in scales, arpeggios, melodies, etc., helps you fine-tune your sound/tone.
2. Especially when you are new to the guitar, practicing various scales can help strengthen your fretting hand and will allow you to move between various chord shapes/voicings more easily.