Random headcanon: the reason that Peach and Bowser don’t seem to get a lot of respect in some Super Mario games is because the Mushroom Kingdom is kind of a rural backwater and isn’t terribly important or influential politically, so people tend to regard Bowser as a C-list villain for being so hung up on such an insignificant conquest. Nobody really expects Bowser to be a serious threat – that would be like expecting a guy whose main claim to fame is repeatedly failing to conquer Wyoming to be a serious threat – so they get taken by surprise every single time.
So what you’re saying is that Bowser is more or less on the same level of villainy as Dr. Doofenshmirtz?
Oh, quite the opposite – point him at any target that isn’t the Mushroom Kindgom and he’s this massive outside context problem that rolls over entire armies and cracks planets in half. It’s just the Mushroom Kingdom in particular he can’t seem to figure out, and that bothers him terribly.
The obvious implication is that, like, Mario is an A-tier hero who happens to live in a C-tier nation.
Like, if Clark Kent hadn’t moved to the big city for a reporting job, he’d still be Superman. And there’s be some villain who tried to knock over a bank in Bumfuck Kansas and wound up having a very bad day.
(And eventually we have Lex Luthor spending a huge amount of time trying and failing to run some penny-ante scheme in rural Kansas and failing, and no one can take him seriously despite the fact that he’s just as competent as he would be in canon.)
In Oregon there lives a species of snake capable of surviving tetrodotoxin doses strong enough to kill animals thousands of times their size. This is because they evolved alongside a species of poisonous newt which they consume regularly, which produces ludicrous amounts of a poison thousands of times stronger than cyanide. They got to this point by fighting each other in the same bumfuck nowhere habitat for millions of years. The newts got more toxic to fight the snakes. The snakes got better immunity to keep eating newts. Now we’re left with snakes capable of eating some of the most poisonous creatures alive, and newts so deadly that they are inedible to anything other than these snakes.
What I’m trying to say is that Mario and Bowser are the result of two evenly-matched overpowered idiots fighting the same battle for decades. The consequences only become clear when you square them up to literally anything else.