Because Agawa presumably will get better too...its obvious atp that shes traumatized and just uses sex as a cope mechanism like people pointed in past comments, but her feelings for the Gotou version of the beginning of the series are starting to leak out. So i expect her to fight for him or something like this? I think this can happen if they have a fight and Gotou just refuses to simp and cry all over her.
And also, who do you think that suits Gotou more than Agawa? Akito just got corrupted, but she has time to go back and just live properly, bc atp shes just having sex with the guy she likes (and obviously Gotou doesnt deserve her). And Prez? We know shes diabolical and super super into cuck stuff, i dont think she would settle for Gotou either, if anything, shes gonna cuck him if she notices that he have feelings for her. Right now Prez truly likes Gotou because of the cucking aspect that shes inflicting in others (Inukai and Agawa) and Gotou is the person that she chan use satisfy her kinky. But if our boy starts loving her, i think hes just gonna be her next victim.
Agawa is a slut, but right now Gotou is literally the perfect picture of first chapters Agawa. I want him to dive more into this path, and if Agawa truly likes him, i want her to fight for it. I know that this sounds like im defending Agawa, but the true is she pissed me off so much in this series, i still remember that one guy who she leaves with in front of Gotou saying that hes as good or better than him...like wtf.
So yeah, i think Gotou and Agawa are truly suitable to each other, but for this to be satisfying for me, i want her to fight to gain his heart not just his dick. A scenario that i imagined would be like inverting the paneling of first chapters now showing Agawa seeing Gotou walking in love motels with different girls often instead of Agawa
Because even though Gotou got Shiina and Akito, hes not even closely as deep as Agawa reached in her diving into slut world. In fact, Gotou still has some emotional connection with both his sex friends, differently from Agawa with her fwb. We could see in past chapters Agawa seeing him with Akito and Prez through the window, just like Gotou saw Agawa and Yuki in the begining. So if they really have a fight or just part ways next chapter, would be really satisfying seeing Gotou being the one who can have sex with anyone and Agawa being the one thats in love with a slut (after this, i would feel that both of them can be together in a much more equal standing).
Sorry, i was trying to just answer you the reason i think they would stick up together after Gotou gets better as a person but i just started yapping again about the sequence of events that i would like