In my humble opinion, based on about 22 months experience (18 of those in TAC), I believe that more concentration is required in the beginning phases of learning but the goal is to move what has been learned to your subconscious.
When you drive your car and you see a child running out onto the road, do you concentrate while applying the brakes? No, this has become a reflex and it is automatic. When you were learning to drive you had to think about where the brake pedal was but that was a long time ago. That’s a simple movement and what you do with your fingers are far more complex, but these movements also become automatic, part of your “muscle memory”.
Concentration might be required to remember the chords and which strumming or pick pattern you are switching to, when the chorus begins and the bridge etc. But many of these can also become more automatic as you do them more and more. I like to practice in front of the TV, now my brain is split between focusing on the plot of the show and playing guitar. I’m trying to fast track the move to my subconscious mind by putting the show I’m watching front and center while I try to play without thinking.