Ok, that is a fair point... but having a ready to play backup does make it more likely he is traded when we could use the money to (potentially) sign someone else that doesn't have a backup (Woo/Burnes). Even though signing any of the 3 is probably low.
It isn't TB where Adames was traded to make room for another player, but Turang being ready to step in at SS lessens the sting of trading Adames (at least on the field, not as a leader).