They didn't leave because they wanted to be starters at Barcelona, they left because either Barcelona wanted them to go or they weren't playing at all. They weren't thought of as good players looking for game time the way you're describing them now, they were criticized and bashed by everyone who talked about it since at the time Madrid had the likes of Danilo, Kovacic, Lucas Vasquez and Morata on the bench who apparently were the best thing since sliced bread at the time.
Now both Alba and Suarez have been overplayed. Digne would have been perfect to rotate with Alba and Paco Alcacer would have been great to rotate with Suarez instead of loaning Kevin Prince Boateng. No need to spend 40 million on Malcom with Deulofeu around either...
The treatment of Andre Gomes at Barcelona was a complete disgrace, the guy geniunely got depressed about it. Came out saying he didn't even enjoy playing football anymore and that it got to a point where he wouldn't even leave the house. It's been great to watch him succeed at Everton, fully deserved.
http://www.sportbible.com/football/...nterview-about-his-current-situation-20180312