I see Adolin as a model child who at every point of his life has done what his environment expected of him.
Him deciding that killing Sadeas was OK, no matter what others say, is an important bit of character evolution IMO.
Also his fashion prowess is comedy gold.
Adolin grew into a role - the role of Dalinar's model scion. His identity was shaped by that role, and he was comfortable in it, but as he gets more agency and more relevant choices, he's growing out of it..