Messi is a better playmaker, sure. However, the thing that means the most in football are goals.
Maradona wasn't the goal scorer that some of the greats are, but he's among the top 2 or 3 players of all time for the majority.
And Messi isn't just a better playmaker. He's much better at Ronaldo than dribbling and take-ons and passing.
Ronaldo has one job with Madrid: score (with penalties). And he's other-worldly at that right now. He's one of the greatest strikers the game has ever seen.
But Messi's isn't just a striker. He's the complete package. He's already at age 27 being talked about as one of the greatest the game has seen, arguably only Pele and Maradona have the resumes to match or exceeds Messi's (WC being the main thing).