Here's the thing. Ronaldo (I don't normally speak about Ronaldo when Messi is the subject, but I'll make an exception this time) keeps his consistent scoring against the best sides. Hell, in recent seasons he's scored more goals in decisive games than just about any other player. And Messi, in comparison, isn't deciding these matches anymore. Messi doesn't score a lot in the big games, his scoring rate is very low. But he also doesn't dominate the midfield in these games either, so you could say that he is this great AM now. So, what exactly does Messi do in the big games lately, beause outside some goals here and there and some bits of genius at times. His consistency in anything, being goals or chances created, is rather low. Isn't an elite scorer anymore, his explosiveness has declined majorly, and his genius passes are picked up by any serious team with some good defensive discipline.
In short, Ronaldo is a better no9 than Messi is a no10 in the last years. I don't see Ronaldo as a poacher and Messi as a total presence in both goals, dribbling and passing anymore. Ronaldo is a no9 and Messi is a no 10 in recent years (again, not talking about games vs Deportivo and Malaga), and Ronaldo just does his job better.
Part of the reason for this is both Messi himself, and Barca & Argentina, who treat Messi as some kind of god who could do anything. These teams should wake the fuck up, and give Messi a precise tactical role, with roles and duties he needs to perform.