The reason for wanting to be near the front of the peloton is so that if a split does occur, you're in the "right" bit. There are less risky times and more risky times to be at the back, but in general its not a great tactic for a GC contender to be cruising around at the back.
Not flogging your team on the very front has merit however. On the bits I saw of the highlights, admittedly limited, Visma seemed happy to let Mov set the pace and sit behind them, & UAE did a brilliant 1-2 raid.
You wonder how much gas Ben turner would have had left had he not had to chaperone Bernal back. Unless Bernal had some tummy trouble or something, that was probably an effort in vain, as if was getting dropped on that climb, he's i big trouble later on (or even today)