I also wonder at this stage of the game, can anybody be able to watch a Marvel movie and understand it or do they have to go back 10 movies to understand the characters?
I don't think you necessarily need to know the entire backstory to enjoy the movies.
For instance, Thor 4. A new audience member may ask, why doesn't Thor have his hammer, or what's the full back story with Jane Foster, but you don't miss a lot of the plot. The most recent Dr. Strange probably makes sense if somebody hasn't seen WandaVision, although it helps.
Thatís how Iíve found Marvel movies. Dance contests and talking animals. Just not for me. I think Iíd enjoy sone of those characters stories if they were more for adults.
I get that. I like my comic book movies with humor and rock music. I love Guardians of the Galaxy. And, even in a Snyder movie like 300 -- perhaps Snyder's best movie -- I though the pure testosterone could have taken a step back.
There's obviously a mix in play. A superhero movie can be great without a ton of humor: see first two Christopher Nolan Batman movies, Logan, etc. And, a good superhero movie can be made for adults, while also having humor (Deadpool).
Marvel movies aren't perfect; they're too prone to fast-forwarding epic story lines (see Civil War), but I find the ones centered around great characters to mostly be very good.