I took the Ronaldo having more to his game than Messi as meaning he evolved much more as three or four different types of players - winning the Ballon Dor as a right winger, left sided winger / striker, all round #9 and then just as an out and out goal poaching #9. Using both feet more often than the very left footed Messi, and possessing much more of an aerial threat. In fact that alone is symbolic of the transformation - from a lightweight right winger, easily brushed aside, to a #9 very powerful in the air.
Messi was also a fantastic genius. But mostly throughout as a small, very left footed #10. So there was less of an all round, complete transformation or two, or three, than what Ronaldo had.
That obviously doesn't mean one produced more than the other in terms of end product, or one was better than the other. But I think all those many variations and transformations of Ronaldo's game is the argument behind him having 'more' to his game in terms of different kinds of attributes and styles throughout his career.
Again, that's not to say which is best as I've already posted earlier that I don't really get involved with saying which of those in the conversation for the true greats of the game are 'better'. I don't think there's any conclusive proof either way. Just easier to say which are the greats who merit being in and around that conversation. The rest is much more subjective.
I get what your are saying, yet, for me the thing with Messi it's that people tend to forget is the great variety of roles he has played throught his carreer (he was born as an enganche in Argentina, a dynamic10). And the variety of coaches he has dealt with, (BTW many not that great ones, would love to see him with Klopp or Mou) with lots of different tactical dispositions and mates.
Messi like any historical off the charts Genius, at some point, very soon played of himself as a wild card.
In the very same match he would display himself on either flank, from the middle, from deep, as a false 9, as a second forward etc.
I actually believe that Messi is clearly better than Cris as a footballer and it could be seen in games were both faced each other, no matter what team won, in terms of producing all sort of plays that goes beyond a final ball, a pre assist, goals or assists.
In terms of playing in more congested areas, of facing tactics more focused on him by rival teams, in terms of ability with the ball in passing, dribbling, in terms of vision, team work...lots of strict football sense stuff that even as great as Cristiano was, he didn't had at that level.
Yet I still get that Cristiano as a forward is a complete package, regarding the tools avaiable for him because of his traits. But in terms of "more to his game". Not really for me, in fact what happened to Diego, Pele and Messi it's that they end playing as main man of their teams, playing many roles at the same time and closer to off mid players with wild card "tasks", due to the weight of their own talent.
If we actually analyze these free fellas and play a game of what role they could have been the
perfect version of it:
Messi is the perfect little forward a la Romario, lethal if a team just used him there upfront as main receiver.
Pele is the perfect athletic stricker and Diego it's a perfect winger, the thing it's that it would have been a travesty to use them in just that role, so they naturally end playing of themselves. That's way many coaches from Messi talk about him as uncoachable, in a general sense you don't tell them what to do or how to do it, as much you give them tools, enviroments to make them participate more and do
their thing.
PD: Also as a side note, his right foot has been the main culprit of many of his greatest goals and this is also pretty much not noticed, he has more right footed goals for instance than some elite goalscorers, he ain't a predominant long shot right footed player, but he'll still have quite a number of them, yet lefties indeed are always lefties.