He can get the most out of his last years if he learns to be patient, and get used to having minutes without touching the ball. Trust his teammates, work to find spaces as advanced as possible. Stay away from super-heavy traffic which all teams block like crazy these days with 4-5 men. Drift a bit wide. He had a crazy good action a bit on the right with a prime-reminding dribble. His area is still right side forward. Even his shot came from there.
All that talk that he drops because nobody can create is bullshit. At some point he was going into Pjanic bothering him with his position, and that was while Pjanic was running hot pulling the strings. It's clear he doesn't want to give up his role as a playmaker, even though he is not a very good playmaker anymore.
That touch he missed at Pjanic's pass. That's Messi losing the touch of a forward. He needs to get that back or nothing will improve. A player of his quality should always shoot on target from that.