maybe Mbappe stay at PSG can help his team win the UCL title (even though it's impossible) but the fact is that PSG will still have difficulty if they only rely on Mbappe because they are not strong enough if they only rely on one player without having a solid line up. meanwhile, to be able to win a title at UCL you have to have strong cooperation, whereas PSG doesn't have solid cooperation for me.
regarding Mbappe move in january, he won't be moving, but if PSG keeps him until June, it looks like he will leave as a free agent and PSG will suffer a loss if he leaves as a free agent.
They have tried all kinds of things and I am sure you are aware of that. They bought Neymar, then they bought Mbappe, then they bought Messi, Donnaruma, Ramos, several other players and yet it turned out it wasn't enough. It is proof that you can't buy the Champions League trophy with cash. They really have tried everything they could except for one thing and that is a great coach. They mostly had average coaches when we are talking about the best. Like the most average from the best. But when they want to increase their chances to win the Champions League, they would need the best of the best. Enrique is ok, but really no magician and not known for being a genius coach.
We will get to see at what level PSG truly is when they play against Real Sociedad. For now it is hard to tell when they play against weaker teams in Ligue 1.