Alexis does a lot more right these days than wrong. For example, let's take a look at his skill set:
Pros
-dribbling
-movement
-passing
-speed
-transition play/counters
-tracking back/defense
Cons
-finishing
-aerial abilities
-holding the ball
-losing possession
-physicality/strength
I will maintain that Alexis vs Alexis has always been the main problem. It was less about his qualities as a player than it was about being in his own head and underperforming for so long that frustrated Barca fans (I was leading the pitchfork party in that respect). Yes, the ordeal lasted for over 2 seasons but now that his confidence is steadily soaring, I want to see what else is in store for the Chilean. Something tells me we haven't even tapped his full potential yet.
Tito and Pep failed to help Alexis play a supporting (yet vital) role at Barca and that could have been why he suffered so long. Tata has seemed to keep him confident which has worked wonders and he hasn't really minded being a supporting role. This for someone who is used to being the head guy at a club (Udinese/Chile). Tata deserves a ton of credit here. For the first time, I see Alexis thriving with other dominant Barca players, something even the great Ibra couldn't do, so I wouldn't want to disrupt that chemistry. As I said, his good outweighs his bad (given he stays confident).
I disagree with a few Pros.
For instance, Alexis is not that good a dribbler. He is good in open space, but in constricted space with players marking him (his role for Barca) he does too many sideway moves that end up with him tripping on his own feet, getting dispossessed, or a backwards pass. Statistically, he has barely averaged a dribble per game for Barca. This season he seem a little braver, but still I would not call him a dribbler.
His movement off the ball for the role he is asked to do for this team is also nothing to write home about.
His work rate is high, but his defensive contribution is really overrated.
I would also add first touch and balance to the list of Cons.
The problem with Alexis was he was brought to fill a role for which his skills are suitable. However, circumstances change that. When Alexis was brought, Barca had an in form Villa, and in form Pedro and Messi. Three players who fit the profile of direct, incisive forwards. What the team lacked was a creative support forward.
What happened was Villa lost form and got injured, was never the same, and Pedro's form also took a big dip. That forced Alexis into a role that was not suitable for him, that of the direct goalscorer on which the team depended on every game. Understandably he struggled and it hit him psychologically.
Nothing has really changed personnel wise still, but Tata has obviously told Alexis to play to his strength and what makes him comfortable. He has gained in confidence and shed his mental block, but that still does not change the fact that his skillset is not what this team needs. Alexis would excel in a situation that would afford him freedom, both positionally on the field and responsibility-wise, as in him not being required and depended on to scored every game.