A player that couldn't make it on the pitch for PSG bossed La Liga last season. That player was Guedes. Kondogbia was sold by Monaco because he was in the way of Bakayoko, he then failed at Inter, before falling to Valencia and becoming one of their strongest players. Etc.
Can we stop with the bad arguments?
That's a bit disingenuous. Both of those are examples of young players developing over time, who hadn't previously broken out until they got to Valencia. You're really flaming a 20 year old at the time for not breaking into PSG's lineup? Kondogbia wasn't even bad for Inter, had some good seasons early on where he was rated well.
The difference is I'm talking about players in their prime or after their prime who show clearly abnormal peaks once they get into Ligue 1. I mentioned Neymar and Zlatan but it doesn't even come close to ending there.
Di Maria was shocking for United and has been for Argentina for a while but became a key player for PSG. Falcao tore his ACL and looked finished and then went on to be great for Monaco. I can easily include guys like Balotelli, Thiago Motta, Luiz Gustavo, Alves who is a beast in Ligue 1 moreso than he was in Serie A, etc.
I'll even say that about Depay because, even though he's young, he already broke out big time at PSV and then clearly flopped at United before becoming incredible for Lyon and dominating the league statistically.
It's a much bigger pattern than the reverse cases.