If recent Marvel movies all look the same, it's by design. If Marvel wants to keep a consistent narrative voice through all of their films, they also need to keep a consistent visual voice. Marvel has developed a "house style" that makes sure that all of their films have the same visual tone, approach to cinematography, editing pace, costuming and art direction, and style of special effects. This visual model has been mostly patterned on the style of Anthony and Joe Russo; they have a clean, streamlined, sharp take on action and atmosphere that is easily digested and replicated.
There have been a few deviations from Marvel's house style, but they are rare, and even then, the deviations are relegated to a few individual scenes or specific shots and not so much the overall film (Thor Raganarok, for instance, has some cool battle shots that look like something out of a Baroque war painting, but other than these shots and some funky '70s album cover art design choices, the film looks and plays pretty much like all the other Marvel flicks).
It's difficult, and maybe even impossible, to differentiate between a shot from Infinity War and a shot from Civil War or Doctor Strange. These films look and feel the same, to give the audience a comfortable and consistent experience as they go from movie to movie. The Marvel Cinematic Universe is sort of like a TV series; you'll need to watch the previous entries to understand the latest release, as if they were episodes in a serial show, so you want the viewing process to be smooth. If Iron Man 3 bore a specific director's fingerprint, showcasing his or her particular imagination, and then the next Iron Man film had a completely different look, feel, and visual tone, they wouldn't seem to all be part of the same overall continuity.
