The rivalry has kind of ended a few years ago already. It was a bit of a slow process for us fans to understand that the big times between the two GOATs are over. I will definitely miss those times as it is still hard to imagine that we will get to see something like that again within our lifetime. We have been quite lucky to see Messi vs. Ronaldo in soccer and Federer, Nadal and Djokovic in tennis. I don't think that even Mbappe and Haaland can get close to that. If you take the number of individual titles or Ballon d'Ors, what is the chance that Haaland and Mbappe will 12 of them in the next 13 years?
Haaland can still do it and I'm pretty confident about that, as for Mbappe, it depends on the result I think. He is a very good player only when he is money-oriented thinking and still remains at PSG even though he has talent and is very good he still will not be able to enter the real realm.
I believe Mbappe will be successful in Paris SG. I must say that it has been successful so far. Messi and Neymar will leave the team. In this case, the main team of the team will chase the victory with the success of Mbappe. I also see a bright future for Mbappe. He may leave Paris in the coming years, but I don't think he will this year.
When you talk about the future it is worth following the news closely these days as Mbappe seems to have announced that he is not going to extend his contract with PSG for the time being. It also seems that the PSG bosses have decided against keeping him for another season before he can leave as a free agent. Therefore, your assumption that he will be successful in Paris in the future is at best speculation, if not even contradictory if it is already clear that Mbappe will in fact leave the club. I think we will know more in a couple of days or weeks.