unlike original mary sue which usually flawless/perfect
as long as a female protagonist do no wrong in the story and still well liked by other characters (or have more than one man having crush on her), I will also casually call them mary sue, especially if they're deliberately drawn cutesy/prettily.
if they have flaws, it's usually fall into "cute" category such as being clumsy, directionally challenged, or unable to cook (played in cutesy way).
anyway it's a common phenomenon for a female reader to find a FMC's annoying just because, especially if they aren't relatable

while everyone seems to dislike the MC, I actually like this type of Mary Sue/damsel-in-distress character for once. Maybe I just don’t mind her that much because Jade is so cute, and the way his mind works ten times better than anyone else’s, especially when it comes to her, is honestly adorable
I also kinda hope this will be continued, since the last time I read it was on Bato. The MC meets Jade’s parents, and they’re hella gorg (not to mention them readily accept mc as in laws I'm laughing)