You can never compare Mbappe with Ronaldo first because these two are different and, to be honest, Mbappe could never be a good leader in his team even in PSG there were some players who hated this player. Now I think since Real Madrid hired Mbappe as a superstar of this team and helped them achieve titles like Ronalod helped this team they expect much more from this player but still, Mbappe could never be the good player they were expecting to see from him.
The question is, why we must compare them?
Ronaldo is one another level, he is a truly legend in football. Meanwhile Mbappe is a footballer who is in his way to be a legend in football.
Ronaldo already proves everyone that he can succeed in any team. It is different with Mbappe who still tries to prove his capability in another team.
So, basically Ronaldo and Mbappe are in a different condition. We can't compare both of them.
However, maybe Mbappe just needs some more time for adoption to be a good leader for his team.
Good leader? I don't think Mbappe will be a good leader because he looks a bit individualistic. I think there should another player in Real Madrid who can be better to be the captain or leader. In the future, I think Bellingham looks better because he has a nice characteristic.