First of all, Richard Donner's "Superman: The Movie" came out in 1978, the Marvel Cinematic Universe started out in 2008. That's a 30 year difference. Cinema and audiences have matured since then.Watching Marvel movies is like watching a (young) kids cartoon but with real live actors instead of animation. No threat, no suspense, no thrill. Plus they're so formulaic that if you've seen one you've seen them all. Give me Richard Donner's Superman, Tim Burton's Batman, Christopher Nolan's Dark Knight, Brian Singer's X-Men, Sam Raimi's Spider-Man, Alex Proyas' The Crow, heck even Ang Lee's Hulk! At least these directors have talent and vision!
Donner's Superman is more childish than anything in the MCU...
Having said that there isn't a single stupid Marvel movie style joke in the entire film. Clearly you are mistaking Richard Donner's Superman: The Movie with Richard Lester's 2 Superman sequels.
Secondly, Donner's Lois Lane's death and Superman's turning back Earth/time scenes have more drama than the entire MCU movies combined.