And that's where we differ. I don't think Cristiano peaked as highly. Messi did (though I believe R9 would've been even better than Messi if he had been allowed to mature without injuries). I have him as more or less equally talented because Messi has this incredible passing ability while R9 is even faster, more explosive and stronger than him. But Cristiano? He got 100% out of his talent which is of course immense but R9 in his prime, even if he only utilized 80% of his, is simply superior IMO. He did things Cristiano was never capable of and I don't think that's the case the other way round. You don't see skills or goals of CR7 where you say "wow, Ronaldo could never have done this" bar maybe the headers, the freekicks and the extreme long range shots but when you watch a compilation of R9's prime seasons, there are so, so many scenes which Cristiano never even came close to.
I disagree with the comparison with Messi. Dont think R9 would have been better either, or even particularly close to Messi. Even so, its pointless to argue about this because we simply will never know.
But see, prime R9 was a 10/10 striker. No player in history can be voted ahead of R9 for the #9 position. You can fit him in any system and he wont be beaten by anyone.
Messi wouldnt be a 10/10 striker, he is probably a 9.5/10 striker, better or just as good as any other striker in the history of the game not named Luis Ronaldo Nazario. Ill give you that.
But then, outside of the pure #9 position, Messi beats R9 anyday by a comfortable margin. As a RW, Messi is the GOAT, 10/10 and R9 could never best Messi on his best position. As a false 9/center forward, Messi is the GOAT and R9 could never best Messi here. As a CAM, Messi is a 10/10 and R9 wouldnt even come close to Messi.
So no i dont think R9 peaked as high as Messi nor i think he would have been as good as Messi, even in this hypothetical universe where R9 stays 100% fit. Not even on the late stages of his career did R9 show half the technique Messi has been showing since 2008 when it comes to passing and controlling the game. On pure shooting and dribbling ability, i dont think R9 can be called equal either.
What R9 had over Messi was that he, on top of being faster than even prime Messi, he was stronger so he could take on defenders easily, but then again Messi is no weak boy either, and even if he rarely gets caught by defenders because of his utterly ridiculous dribbling and ball control speed, the times he does get caught, hes no easy to pushover by any means. But yes R9 was stronger, a tank and a jet with or without the ball.
With CR7 the comparison is something similar, except LW instead of RW, and without having the arguments Messi has in his favour in regards to passing ability. Other than that its pretty much the same. Yeah its closer IMO but still i would pick CR7 over R9 longetivity wise, and peak-wise i dont know, i guess it depends on the rest of the team. Cant go wrong with either one IMO.