Any drill has great benefit; scales practice adds music theory and understanding. Running through scale patterns has helped me lick some bad habits/improve my technique; e.g.. fly-away finger(s), using the tip of my little finger vs. the pad, keeping my hand parallel to the neck and fingers vertical, brought the little finger up to the same 'capability' as the other three. Fret hand flexibility, stretch, strength and picking improvement are all benefits of 'drills' and, IMO, scales have that added benefit of better music understanding.
Further, running through scales is a great exercise for me to focus on relaxing my grip and whole body while maintaining proper posture. Improved my timing, too.
But then, I started with low expectations... :rolleyes:
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins
-- Chet Atkins