Manga that display interpersonal relationships like this feel so fucking gross to me, it's the whole thing about treating others as NPCs that give you pussy when you level up enough.
It's very odd. I really want to understand the people who make these.
Are they completely cynical creations meant to pander to the lowest common denominator? These series basically function like madlibs at this point. Just add a "cute" girl that fits into one particular niche, pick one gimmick (she's your manager. She's mentally ill. She is 3 feet tall, etc), add RPG/dating Sim mechanics and/or some kind of deadline, and then call it a day while waiting for...IDK what to roll in. Potential serialization? Twitter views? Negative attention? NSFW requests?
Or maybe the people who write these are totally into it and think it's a great way to spend their time. It's a big trend in wish fulfillment series to convert the abstract (relationships, skills & abilities, progress, whatever) into quantifiable stats with an unambiguous pay-off. Even ambiguity within character actions or archetypes is typically not allowed. Girls are tsundere, kuudere, childhood friends, oujous. Everyone of dating age with good looks is inexplicably single. You don't even have to think about it. Villains are usually completely insane with no redeeming qualities and protagonists are typically not allowed to have any real flaws or failures. I think that's part of the wish fulfillment, but I also think not immediately knowing what's right and who's wrong in a story can be upsetting to certain people. Stories with predictable outcomes become comforting instead of boring.
I'm thinking of otome iseikai/rofan stories that I've read, in addition to these twitter series that show up on the front page, but a lot of readers and writers literally do see these stories as completely protagonist centered with the other characters being, basically, "NPCs" (like you said). What's good for the protag is morally good and logical, no matter what it is, whether it's "deserved" or not. On the one hand...that's the wish fulfillment but, on the other hand, it gets weird.
And maybe the authors know it's bad but they just sketch/brainstorm without any intention and this is what naturally comes out. 🤢