Yeah, but that's just another pointless false equivalency. Ronaldo did use his talents. He reached the pinnacle of the sport individually and collectively. He just didn't do it for as long as some would want. And that's fine - everyone has their own opinions.
I'm assuming the OP used the R9 comparison with Mbappe because he's not only a similar player in terms of skill-set, but because they both took the world by storm at such a young age. It makes sense.
This is the problem with these debates. Everyone has their set of arbitrary conditions , and they think they've created the absolute truth. When in reality, when it comes to great players, the "truth" is highly contextual and subjective depending on the set of eyes viewing it. Biases exist , and we're not perfectly objective observers.
And worse, people feel simplistic stats or team accomplishments provide all the answers. They don't. Maybe in baseball where it's essentially an individual sport with the same isolated action over and over , but not in football. Everything is far too symbiotic.
An opinion is just that , and acting as if yours is the unquestionable truth is just an act of supreme hubris.
Some people think Manning or Rodgers is better than Brady or Montana , others think Lemieux is better than Gretzky , some say Bird was better than Magic or Lebron over Jordan... and on and on and on. There's reasonable thought towards both sides of the argument that goes beyond stats and team achievements. I , for one, think the rings argument is incredibly simple , for others, it's the end-all-be-all.
For me, when completely healthy and in top form, if I'm picking someone in a vacuum to win me a game in my backyard , I'm taking original Ronaldo. And I don't think it's particularly crazy to think that way. That, to me, is just as good of a litmus test towards true talent , as any other method those have deemed as the "truth".
In the end, it's all subjective , no matter how you want to dress it up. I think it's important to acknowledge that.