I'm so normal about Maxie. He's so complex and the general fandom never reads his ORAS dialogue enough to understand that.
He's distant and formal, yet somewhat sensitive and dramatic (as seen in the Seafloor Cavern). He's rash and stubborn, but has a strict moral code and follows it heavily, meaning the best for humanity (just corrupted by the mentioned stubbornness). He can be read as a perfectionist, and likely relies on routine to feel stable (the morning meeting). He cares about others but tends to be impulsive (In Pokemas it's more evident, he has dialogue where he says he tends to ramble, and in the delta episode he apologizes for not thinking of Courtney first, so he is likely not only impulsive but by the time Groudon's settled, he's aware of it). I personally read that he has HIGH compassion but struggles with empathy (actually reading people's emotions) because of the scene in pokemas where he's like "And I know his feelings are real." About Archie...
I read that scene as implying part of why Maxie continues the rivalry, is not only for his own ideals, but because he assumes it's best for the both of them. He doesn't hate Archie, to me; he wants to improve the world for people, I don't think he'd exclude Archie from it over some personal quarrel (and the symbolism of the model boat). He still wants Archie to thrive and grow, just not. Biblical flood. But, given his rigid morality, he can seem like he hates Archie with the harshness, when he merely hates Archie's ideals.
He can also be overconfident, yet seems insecure in a way to me(?)
I might be biased, but his harsh view toward himself after breaking his own moral code (scene after you catch Groudon) strikes me. I think he's very turbulent in his view of himself and/or others (perfectionism too). He does something right and his mind displays overconfidence, but crashes into near self-loathing upon mishaps, as well.
And the general, non-pokevillian specific fandom just. Doesn't notice. The TrueGreen7 poll for the villains where Maxie and Archie were last fucked me up because DOES NOBODY READ THE DIALOGUE?? DID NO ONE PLAY ORAS??? DOES NOBODY SEE WHAT I SEE???? IN THIS MAN???? Give him a chance. He's not a "simple character" YOU JUST. DIDN'T. LOOK.