The Dark Knight Trilogy was also made before the MCU was properly established. Of course it's not tied to a formula because a formula didn't exist.
Post MCU DC movies suck though. Man of Steel was bad, Batman vs. Superman was horrible for what should've been an absolute hype-inducing movie, and Suicide Squad was a ****ing mess. Sure, Wonder Woman and Aquaman were good, and Shazam! is actually a great movie from what I've heard, but that's 4/6 (I'm counting Wonder Woman and Aquaman as 0.5 each). If that's what "risk taking" gets you then I don't want to take any risks.
You may call it "formulated mediocrity," but MCU movies are also consistently good minus some outliers.