I'm trying to think of the earliest "Western Literature" that you get introduced to that has the darker side of humanity and not coming up with anything until you hit 11th or 12th grade while I bumped into anime at something like 7th grade.
Hmmm, perhaps something by O'Henry or Roald Dahl would qualify. I hit them in 7th grade and liked them very much, too.
One punch man, season 1. So chill, both pays homage to and is an amusing pisstake on the dragonballz kinda idea of heroes, training and "leveling up your power".
And then there is a double episode, around 7 or 8, that is a beautiful essay on "what defines a hero". For me, this was chefs kiss good and defined the series for me.
From what I gather - having never actually watched any - there are anti-war themes (IE armies are commanded by people who don't have to sacrifice, how that corrupts), sacrifice vs outcomes and more. It's a thematic experience rather than an education in robotics or history.
I like stompy robots. I have to yet to start on Gundam because I am hesitant as to where to start and which path to follow in watching it all and I know it would consume me once I start.
Maybe after Xmas, in my break, I'll "waste" some time with it.