Honestly, I'm truly convinced that Takeda's sole mission is to make Gotou's life a living hell. Because when you really think about it, every negative thing that's transpired since the end of the summer school arc didn't need to happen.
Let's not forget, it was Agawa-san who told Gotou to go off and make sex friends. And this was after he chose her and she rejected him. So he goes off, he gains confidence from having sex with multiple women. And at this point, this is something that should have been built off of. But instead, the writer decides that he's going to destroy Gotou's confidence by having him not satisfy Agawa-san, the one person he's been simping over this entire time.
Gotou ends up developing ED and then going through a series of events to recognize that the reason he has this ED is because he disappointed Agawa-san, the one person he's been simping over this entire time. Now he finds out that Agawa-san been fucking girls too, which puts him in a depressive state, which honestly, I don't understand why that would put him in a depressive state. But it's revealed that just because he said he likes everyone, he doesn't understand girls.
So the moral of the story is that Gotou can only prosper and have good things happen to him when he's only simping for Agawa-san. But she can go off and have sex with anyone and there's no moral clarity for her. But he has to go through these series of character development moments just to realize that he should have been simping for the one girl who's been having sex with any and everybody this entire time. Make it make sense.