Guys like Zidane, Platini, Maradona, Ronaldo, etc. even C. Ronaldo can slot into most teams, most styles of play, and help their team dominate.
Messi post-Guardiola (+ prime Xavi and Iniesta) demands the entire team play for him, take all attacking movement through him, allow him to dominate the ball whenever he asks for it. When the perfect team playing that one single Messi-centric style isn't built around him, his teams are easy to stop.