Oh, nice for Neymar, Messi, Mbappe and the like in PSG, they are big stars, people will miss them. It's normal for fans to miss their key plays after exiting the club, if not for the performance in the club, it could be the personal love of that player. I must confess I missed C. Ronaldo when he left Man U, and even how he was treated before the exit makes me dislike Erik ten Hag until today. You can see how the bond between fans and preferred stars could be strong and sentimental. Even when things are going fine in the club, the whole club might be boring to the fan just because his person is no longer there.
Ronaldo left Man Utd because he saw that he couldn't achieve anything good there and he couldn't find common ground with the coach, but before that he left Juventus and before that Real Madrid. I don't know why he wanted to leave Real Madrid, I think it's wrong to leave such a team when you're in your prime, but he did it. And now a player of such a high level plays in Saudi Arabia, for me it's also strange, but Messi also plays in America, not in Europe, so if you're the best player it doesn't mean you can only play in Europe.