I don't think every character has to be relatable to make a good story. There's room for some larger than life personas, especially in superhero movies. But don't try to bring them down to our level. The whole story about Superman being angsty because he's a demigod alien that shoots lasers out of his eyes got old at some point. Spend less time dwelling on the implications of eye lasers, and more on the eye lasers themselves. That's what people want to see when they go see a Superman movie.
It's the same reason I'm puzzled at the Wonder Woman movie. WW1, of all things? Why do you have her fight bog-standard humans? Not only does it seems unfair, but Wonder Woman is the kind of character that should be punching mecha-gorillas on the moon or something. Doesn't have to be this silly, and you can still construct a good narrative out of a larger than life plot, but don't try to bring them into our world, they're demigods, they don't fit into the real world by design. It's like when FOX tried to fit Deadpool into their ''serious'' narrative in X-Men Origins. The character just didn't fit the story they wanted to tell at all. Same for trying to make Superman and co. gritty and grounded.