In defense of one-dimensional characters

Screenshot from The Gamer
American media seems to love complex heroes, especially morally gray ones. The characters who will break the rules, but do so in pursuit of a goal that the viewer/reader supports, make it ok. Butcher in The Boys is one example. He's a bad husband, absent father, liar and killer, but he's trying to take down Homelander who is objectively worse, so the viewer can overlook his flaws. Our heroes must have a dark side and our villains have to be sympathetic.
I think it's exhausting.
I'm not arguing that every character needs to be overly simplistic, or that there can't be personal growth, but it seems that popular stories focus nearly exclusively on moral ambiguity. Butcher suffered great personal loss so the expectation is that he'll do bad things. That inner struggle, which he may overcome (the series isn't done yet), has periods of ebbs and flows. There seems to be a belief that characters who act in morally ambiguous ways are more realistic, but I don't think that has to be true.
The genesis of this post came from a recent playthrough of the first Mega Man Star Force game (well, partial playthrough, it's a long game). This was a series I missed when it first came out so I'm playing it for the first time as part of the new legacy collection, which is a really excellent way to experience it.
Before I picked it up, I spent some time reading both modern and contemporary reviews. One of the main themes I noticed was a complaint about how simplistic the plot is, that there isn't much nuance to it. After putting in 8 hours so far, I'm not sure why this is a complaint. Yes, characters can be considered one-dimensional, but the hero Geo still has personal struggles he has to overcome.
The basic plot is that Geo's dad went missing on a mission in space and because of that he's retreated into himself. He doesn't go to school and he spends his nights looking through telescopes, searching for his father. The first inter-personal conflict surrounds the class president and her "goons" who are trying to get him to come back to school. That's it. We have a young boy who feels out of place and the first "baddie" is trying to get him back to school.
Throughout the next 15+ hours we see other characters struggle with a sense of belonging, but there's very little moral ambiguity. Nobody engages in antisocial behavior because of their situations, they still find ways to work together and achieve common goals. I think this paints a better picture of humanity than what popular media typically portrays. Bad things happen to the characters in Star Force, but they don't use it as an excuse to do bad things. Having more stories that show this isn't the weakness some reviewers think it is.