I don't know, I think the mundanity of repeated alien invasions, wizard battles, and a mad scientist turning half the population into giraffes for an afternoon is it's own kind of "grounding." This is just how things are, so the real drama and conflict is mostly interpersonal and still relatable.
Also, yes there's people flying around with goofy colourful outfits with silly codenames, but it's not shrinking from the horror and carnage that would ensue from these people getting into fights in populated areas. And if it seems messed up that a world would just accept this as reality and go on about their lives, that to me is probably the most grounded aspect of the premise: "Fifty bystanders were killed today when a deeply misguided lone wolf assailant turned into an actual wolf in a local shopping centre. The mayor released a statement saying his thoughts and prayers go out to the families and victims of this unavoidable tragedy."
If that kind of thing doesn't sound chillingly familiar, then I envy your ignorance.