I think the MCU movies are fun to watch. I think Scorsese films are fun to watch. Not sure how often Scorsese reaches the whole category of cinema, either, if I'm being honest.

Personally, I think Ragnarok is the best MCU film. For something that's one part Flash Gordon and two parts MCU and all humor, its portrayal of all the characters struggling to find their meaning and purpose in the face of setbacks is incredibly fun and lighthearted. Honorable mention goes to Logan, too, even though it's not an MCU. It's surprisingly tender in the way it approaches a bunch of aging superheroes/actors finishing their life's work before they go. Also Super, not an MCU but is James Gunn. Really a great dive into the ludicrousness of superheroes and how fucking broken these people all must be.

Okay, so here's MY take on the difference between high vs. low art, and what all the bitching throughout tastemakers and academia is:
low is specifically meant to evoke the broad brush emotions you described.
High is meant to evoke the subtle details.
Because art doesn't work, period, if it doesn't evoke SOMETHING. But low goes for low hanging fruits, the same way an old myth, faerie tale, folk tale, or morality play does. Because those are the easiest emotions to evoke. It's like the difference between horror films and slasher films. A slasher film preys on your baser instincts of being frightened because we're humans and thinks suddenly appearing while making loud noises makes us pee ourselves and kick in fight or flight. Horror, on the other hand, is that unsettling dread that settles in when something doesn't feel right. If you've ever been creeping around in the darkness of an abandoned building when you were a kid, or gone to a place that should be full of people but isn't, you'll know that something doesn't even have to happen for it to be frightening! There's that wiggle at the back of your brain that just keeps you on edge the whole time because something inside of you is screaming that something isn't the way it ought to be.
In passing, I read a great take down of the difference between horror and jump scare films.

Quote A jump scare is like if the comedian went down into the audience and tickled you. You're still laughing, but it's not from his jokes.

"high art", though, is always a character driven story, because stories are inherently character driven. It's the difference between Maus and an Avengers comic. Maus brought me to tears when he talks to his father about why his dad always stockpiles canned food: Because Hitler might come back. Even as an old man, the horror of the holocaust was burned into his father's mind so deeply that he couldn't ever shake it free. And communicating lifelong PTSD created by the trauma of a global human tragedy that happened generations is just more difficult to do in a theme park story.
Are theme parks fun? Yes. Do they say something? Yeah, of course they do. But it's so broad and so intentionally tugging on the baser things that it doesn't matter.
edit: I shouldn't say "doesn't matter". The best analogy I can think of is that it's like getting two different gifts from two different friends. One is a new car, all paid for, that your incredibly wealthy friend gives to everyone they know. YES! IT's a huge gesture, and it's definitely appreciated, and that's awesome! Go your friend! And you get a free car! How could you NOT appreciate it, right?
The other gift, though, is a copy of a video game you LOVED as a kid that's been out of production for years, and your friend saw it at a garage sale and thought of you, so they snatched it up and held onto it for months so you could have an awesome present. No, it's not a grand gesture, but they knew you'd love it, and it would feel like they were giving back a good part of your childhood. Or it's a first edition of your favorite novel, or it's something they made especially for you.