Why should I have a definitive answer? I don't watch other teams, except few high profile games and highlights here and there. I don't know if for example Salah would have been more deserving last season. In my view, yeah, Yamal is probably the biggest talent and also won enough in recent years with big performances to justify winning a Ballon d'Or (EC win, CL semi standout performance, countless Clasico performances) but I'm biased as a Barca fan and I don't watch enough other games to clearly make a statement.
What I know, however, is that Ousmane is not the reason for PSG's success right now. That much should be clear.
Dembele is part of the reason.
Successful teams need good players in different positions driving them, like with Man City, there was Pep, Haaland for the goals, KDB, Rodri driving them. With Madrid, you had Benzema, Kroos, Vini, and Courtois.
For PSG, Enrique, Vitinha, Pacho, Kvara, and Dembele is definitely there, except you're biased, cause you can't have a player with the most g/a for a club in their 2 most successful season not be part of the reason (79 g/a in 5,263 minutes) not there - and he delivers in key moments.
In Summary, a good team gives you trophies, and this pushes you for individual awards, even looking at us when we dominated we had a great team, ranging from when we had Eto, Henry, Xavi, Messi, Iniesta, Yaya toure and the likes winning it all in 2009, to when we had Villa, Messi, Dani Alves, Iniesta, Alba, Xavi, Busquet became key, or even with Suarez, Neymar, Messi becoming deadly, so if our team doesn't improve and we don't win major trophies, there's no way Yamal wins anything, and can't blame anyone for that