Not sure whether the ending was pre-planned or rushed but the fact that it's difficult to tell also means that it ended well enough. I would've wanted more but it's good enough. I can't wait for the mangaka to return with another series. It was a fun ride.
@Afeinia
The context matters. All of the characters in the speech bubble that you pointed out are "大丈夫ですか? 情緒が". In my understanding, that can be translated to something like "are you alright? [asking due to] the atmosphere (mood)". A portion of the sentence was omitted because it can be...
I found the original japanese web novel version (i checked shyousetsu), which the manga version was adapted from. Unfortunately, it has no fanslations (i checked novelupdates). Link ~ https://ncode.syosetu.com/n5613hl/
It's nice to know that somebody else too can see the flaws in the plot. I read somewhere once that an author can't create a fictional character smarter than themselves. If the author has poor socialization skills, then they can't create a character with great socialization skills on their own...