We should have a well trained team with chemistry between the players, understanding each other and knowing when to move, where to move, when to ask for the ball, when to stretch the field, when to come closer. Training as a team, working as a team and playing as a team. And on top of that, Messi would be able to show his game. A team who has Messi as a bonus, not as a must to properly works.
But no. Like a lot of people said, every single ball is aimed to him and lots of times he's not well positioned, he's marked by 2 or 3. The team should play like usual, and then when the ball comes to him, he could do something. Forcing moves, forcing passes, just to give him the ball, it's not the way football works.
Barca spent a lot, and will spend even more, but it doesn't matter if you have the best players in their position, if you can't make these best players to play as a team, as a unity, all together.