Man I feel like we're gonna get blueballed and we get an inconclusive ending (like all manga with a theme like this). That being said, I do like the fact that the best and kindest girl got to be in the spotlight, and would become the clear winner should the manga go the unconventional route of actually having a good ending.
Shirai the cinnamon roll, she deserves it
I kind of disagree. Beyond the fact that the loli twintails is the most wholesome and cutest cinammon roll (with also the most character development because she used to go along with the other two and was meaner but then moved away from that.)
It's also kind of against the point of the series, it's a manga about mesugaki to begin with, the fact she's not a bit bratty ought to be a disqualifier, it's basically just the most boring choice, and for a manga whose draw is the exact opposite of it.
Obviously you're never gonna get anything great from a sudden axe but Shirai is just being used as a vessel to force the others to act, at least if the writing makes sense.