What the Marvel Cinematic Universe has accomplished is nothing short of a miracle - back when it launched with Iron Man in 2008, the idea of a connected universe that spanned multiple movies being released each year, utilizing characters frequently crossing over, was basically unheard of. It was a laughable dream that came true through Marvel's planning, persistence, and savvy execution.
And while they made the world fall in love with the universe and the characters who dwelled within, there has long been complaining about the MCU's aesthetic deficiencies: namely that they're blandly directed and even more blandly scored.
A lot of this is hard to argue with - there's no question the Marvel films lack the visual panache that directors like Christopher Nolan and Zack Snyder brought to DC (yes - for all of Zack Snyder's faults, he remains a pretty incredible visual director). And as for the scores...well, we could try to summarize the issues, but thankfully YouTuber Every Frame a Painting has done an exceptional job explaining the problem with MCU film scoring - as well as the larger issue of film scoring across all Hollywood big budget productions:
A lot of this is pretty astounding, if you weren't already familiar with the politics around film scores and the problems with temp tracks (along with the shaky relationships many filmmakers share with composers in negotiating the tone of their films). EFAP also created this supplementary video to give some further examples of obviously temp-influenced scores:
Not that all hope is lost or anything - there are still big films being made with fun, memorable, and original scores being made - Wonder Woman's theme from Batman v. Superman being a prime example:
No matter what you thought of the film (here's what I thought - hint: I DID NOT LIKE IT VERY MUCH), most would agree it had hella good music and a lot of amazing visuals.
Let's hope Marvel takes the hint sooner rather than later.