Mbappe has glimpses of Ronaldo. He is a severe downgrade though at the moment with some room for improvement. He needs to be more involved in the game from the middle, improve dribbling to Ronaldinho levels, improve shooting accuracy from distance, build up some muscle and thus become someone the whole team has to chase around. Odds say it won't happen. I don't think people know or remember Ronaldo that well
I was laughing when they compared him to freaking Henry. He's already more versatile than him and has the same 3 traits where Henry excelled at (cutting in from the left, excellent placed shot and speed). This kid could do more when he was 18 and it too obvious. He won't be a Ronaldo, he'd already be one if he were. But for sure it's the player that reminds most of R9 due to that explosive speed. Prior to that, I think Zlatan came the closest until Mourinho 'converted' him into more of a box striker. The skillset was almost as good as a R9 copy though, his first step, the acceleration(damn, Zlatan was too fast for his size before joining PSG).