I was about to say practice is good, moving around, interplay is good. I think it's good to improve any area, be it practice, harmonies, musicianship and production adding subs, better tops etc.
I was in a great band, but it fell apart when 2 members moved away. All I had from that band was our lights/stands/truss etc. I got married etc and ended up with 2 stepkids.
When they got the bug and became musicians I decided to bite the bullet and buy a PA to put on all ages shows. So my involvement grew from there. I kept adding to it as I could until I had a full system.
Finally last dec I was able to upgrade the light rig, so it's been a long time coming. But adding a dozen songs with killer harmonies is just as effective if not more. Having a decent system I'm not fighting against let's us perform trouble free, because everything works.
So I think each aspect has its value...