This argument, Ronaldo had a strong Manchester united team built around him and even a stronger RM team. Is barça a strong team yes, does Messi benefit from playing with players like Xavi and Iniesta, absolutely. But he's still superior to Ronaldo in every facette of the game bar FK.
I guess you don't watch RM these days, Ronaldo can't beat a fucking defender these days, he ruined his game when he bulked up like that, he's nowhere near the players he was 2/3 years ago. I used to rate him very high but not above Messi, but now he's just became a very " normal" player and many RM fans agree with me.
Dude, manure never had creative midfield maestro's like barca has, they worked as a unit, Ronaldo brought all the flair into that team. As for Real, they needed time to gel which has been happening as of late & yet Ronaldo still performed, despite the coaching merry-go-round which happened.
My point is, even if you join a team with amazing players, that doesn't guarantee that you would immediately gel & take over that particular league. Ronaldo has done that twice. Messi was intergrated into a system since he was a little kid. Whether he can crack it in another league is a whole story all together. Ronaldo being the prick that he is, has all the tools needed to adjust & cope with a change of country, team & tactics, something Messi clearly can't do.
Messi would totally flop if he had to join another team imo, even if it was a quality team.