True, and you gotta remember that they're still teenagers while Arthur mentally isn't, idk why others keep on pointing out their flaws when it makes the story more realistic. Like, it's normal for teenagers to make a mistake, be ignorant and shit yk.
Plus Tess is really strong, if she isn't, why is she the student council president?
And if you look at it in another perspective, the only reason why she needed saving in the first place is because of the assimilation/something to do with the beast will. When Arthur got chest pains and shit, no one called him annoying or a damsel in distress.

you all hate tess? really? shes awesome. so what if the main character, whos stronger than her, saves her? she a great character and well written. shes just a kid who likes him. shes not overbearing and annoying like ive seen done so many times. i usually greatly dislike most female characters in stories because they aren't written well. tess isn't one of them