Of course he's the problem. Messi has been lazy for the past 4-5 years. It was masked because Neymar and Suarez would do the running for him which allowed him to be free. Once Xavi left and Iniesta got old, Barca lost their dominance and control of the midfield and the problems he has with Argentina, started to show themselves at Barca. Then when Neymar went and Suarez legs went it became more obvious. Then the main focus was on him to create. You cannot play 33 year old Messi as the false 9, unless you have runners around him and besides Fati and Braithwaite. Dembele, Coutinho and Griezmann want to take up the same sort of positions as Messi does. Messi wants and needs the ball to be involved, because that's what he has always done. C dot is happy to chill and not be involved in the attack until the last moment.
Messi's problem is the same as Gooney, cannot play in isolation for long periods without the ball. That's why Gooney tried to reinvent himself as a midfielder, so he could be on the ball more.