Exchanging Griezmann for Neymar could probably be a win-win situation for all sides involved. Off course with no money added. It has to be a player for player.
If you think it is a win win trade for all sides, being a Bar?a fan, it means it is not a win win deal but only a win for Bar?a.
One could say that Pjanic-Arthur was a win win transfer with Bar?a getting rid of a player who has problem to perform and alleged issues in his private life while fixing your accounting troubles. And i'm sure you don't think it is a win win deal over here.
The reality is Neymar is by far the best player of PSG when Griezmann is tasting the bench more and more. How is swapping the two a win situation for PSG lol ? Let's do a Paredes - Frenkie de Jong swap. Win win situation for all sides involved since FDJ has not found his perfect position yet at Bar?a. Ofc with no money added.