People may have different views to me on this but whilst Shaw 100% has the capability, I think his actual output in playing out from the back is incredibly inconsistent and he gets way more props that he deserves imo.
There are games where he plays majestically with cute first time touches, opens up his body and carries the ball centrally to open up passing angles but on average this doesn't really happen. He has a tendency to stand on his heels when pressed and is severely one footed, so his first touch usually ends up with him needing to pass the ball back where it came. If I had to give a specific technical example, he doesn't take the ball on the half turn and his body angle to receive a pass is often poor/lazy.
There are times, where if he doesn't get help with an easy outlet pass or one-two, he will take toe-push-pass a ball for someone to receive in an awkwardly. In the opposition half, he's clutch with crosses and interplays, I'll give him that but in our own half, depending on which Shaw turns up, I don't 'trust' him to be reliably progressive out from the back. Granted, that's still better than AWB and Dalot at left back but that's besides the point. Martinez is number one of course but Dalot (despite his numerous brainfarts) is comfortably, er, our second most 'comfortable' player when playing out from deep.
I'm not saying he's a 'bad' player but I'm critical because I know he's capable.