Barsa is coming out of a phase were their established model was blessed with a golden generation of talent. Puyol, Xavi, Busquets, Iniesta and then Messi as the cherry on the top. When they were on, they were perhaps the best the club side the world has ever seen.
Madrid, without Barsa's model, has had a solid generation of young talent (never on Barsa's level though) together with some very good purchases. Amidst the galactico hysteria, Real have actually been extremely good at identifying and buying young talent at fair prices. Kroos, Modric, Varane, Marcelo, Casemiro, Isco, Asensio...none of those guys were particularly expensive and are all very good at what they do. Add them to the solid squad players provided by Madrid's youth setup and the superstar Ronaldo and you have a contender for winning everything every season.