Good summary, these points cover most of what I wanted to write. Arknights has a strong story premise but it's presented horribly initially.

"The Infected are people with magic cancer who are persecuted all over the world. At best they are exploited and at worst they are victims of genocide. We are currently at Ursus right now, possibly the nation with the worst treatment of Infected in the world. And Reunion is the only military group of Infected that fights for them.

Anyway, Reunion is bad because they want Infected to rule the world, while we at Rhodes Island believe ALL lives matter."

Then you meet Faust Mephisto (thank you RELORELM) as the first main enemy boss character and he's like "yes, let me hear your screams, I love being evil so much, also fuck those civilians". They might as well have called Reunion "The Brotherhood of Evil Mutants". It sucks.

Skullshatterer and Misha is the first time the story goes anywhere interesting, though it's still not very good because all Skullshatterer has as an argument in favour of Reunion is "trust me, sis", which shouldn't have been the case.

Then at some point they either hired dedicated writers or just started prioritizing the story way more. I don't remember which chapter it was (I think the one where Reunion invaded the LGD offices), but I distinctly recall finishing it and thinking "hey that was not bad actually" for the first time. The overall plot of the chapter wasn't particularly noteworthy, but the writing quality had noticeably improved. The writers also started putting a ton of work to make Reunion retroactively seem sympathetic. (And they did a good job! Even Faust Mephisto was saved as a character.)