Of all players active, Ronaldo's legacy is the hardest to frame. He's done some wonderful things and shattered a lot of longstanding records, but at the same time, his legacy on the grandest stages does not match with numerous greats from the past, and he will not have an international tournament of note for his entire career, and that's irrespective of Portugal winning anything, as it's not about only that (look at Cruyff or Puskas or Eusbeio or countless others to understand the point being made).
The modern Champions League also gives modern players on stacked teams countless chances to make a name for themselves and do wonderful things. Ronaldo has a lot of goals in the competition, but since he left us, I'm not sure he's done anything, or had any moments that will go down in the annuls of time of their own merit (such as his wonder goal vs Porto, or the header vs Roma etc).
There's little question of Ronaldo being the best goal-scoring wide forward of all time by now, so in that category, his legacy is assured, but when pitted directly against skilful and creative wingers who were at their very, very best in the biggest games of their career such as Best and Garrincha, I don't think he gets in a team over them.
The barometer for Messi isn't and shouldn't be the same as it is for Ronaldo beings as one is a natural #10 following in the footsteps of a lot of #10's with a similar skilset that can be compared and scrutinised easily and because all those #10's controlled and governed games, it's very easy to deliberate on how much influence and presence they had in their teams, which Ronaldo, by default, cannot attain. Ronaldo came up as a proper winger, changed to a wing-forward goal-scoring machine and will eventually end up as a striker. That in itself is unique and perhaps Ronaldo's legacy has a few more chapters yet that can alter opinion of him further.
Pele, Maradona, Cruyff, Beckenbauer, Platini, Di Stefano, Puskas, Best, Garrincha, Eusebio. That's ten players alone that had amazing talent and constantly rose to the biggest occasions.
Ronaldo, Gullit, Van Basten, Romario, G.Muller, Messi,
That's another 5 attackers, (in fact, apart from Beckenbauer, I've made sure to only mention attackers, the list is more extensive with defensive players added) you'd better have a good argument to say Ronaldo can match up to let alone surpass.
There are countless other players you can add for arguments sake and ask specifically why Ronaldo should be ranked above them. Players like Ronaldinho, Henry, Zico, Kocsic and so on, and I don't think the counters would really stand up.
The lad said it himself: "with me is always polemic." And he's damn right.