#3 It would take the pressure off Messi

Better we stretch back to Barcelona's loss to Roma in the Champions League.
It was clear Messi wasn't having one of his best days. He failed to make the difference in the game and was subject to some unreal hatred and criticism following the fixture. While castigating him, seldom anybody would have thought of the number of times he saved the club in the past.
Why did that happen? Because of the massive burden of expectations that people place on his shoulders.
The amount of criticism levelled at the Barca forward was way greater in contrast to the other individuals who shared the pitch with him that day. It was a fine example of how Barcelona suffered due to 'Messidependencia'.
Neymar's arrival will reduce the pressure on Messi and on rare occasions when Messi has an off-day, Neymar can easily step up to lead from the front, as he has done in the past.