He would have had a chance to play in some game if he had chosen Barcelona, He is very intelligent and skillful and with Barcelona having many young players, they would have let him play regardless of his age if he merited it. Gavi, Pedri, Ansu Fati are all young players but very important to the team already, Arda Güler would have been an important player too because of how he plays. Real Madrid got him so that Barcelona will not just have him and his family had a big influence on the move.
Is that so.. Ansu Fati still hasn't played properly in last season and this is the player who dons the #10 shirt for Barcelona. My point is no club guarantees a young player chances. It's hard to find chances when you find yourself in a top club where there are elite players in the squad. For Vinicius it was bit easy as Hazard wasn't performing and Vinicius was a good dribbler from the start so it was something that gave Vinicius preference over Hazard. Rodrygo also had hard time finding his chances but once he left off an impression of "rising on the ocassion" and scoring some late winners, Real Madrid also found his use also. Guler also has to make his way but lot of it depends on luck and the impression he leaves on the manager in a real match.