Balo's main issue was positioning, lack of tactical awareness. He was rarely where we needed him to be during the transitions to attack. He would push up too early or not at all, stand still and wait for the ball up front, instead of linking up with an isolated Rebic or making himself available as a paceful option on the left flank during the transition to attack.
BUT, once he did have the ball in the final 3rd he almost always managed to beat the defender and send in a cross that reached the 6 yard box. There's clearly potential here - he's not some complete fodder.
Some of the poor decisions are hard to excuse, but it's normal for fullbacks to struggle tactically, positionally initially, especially in our system. They have a crucial role during transitions and it's clearly also very complicated.
Kalulu, Conti, Dalot and even Calabria had similar issues at first. Calabria was a positional mess, a disaster in the first appearances under Pioli, but he slowly picked it up and managed to make the team adapt to him and his characteristics as well.
It's not certain that BT will also improve on these things, but I would prefer not to move Calabria away from his position and cause more instability and cohesion problems than what injuries and COVID are already causing.
BT deserves more chances.