People are arguing two different things when it comes to simulation discussions. The thing they don't want is for the events of the game to have not mattered because Akira woke up and then continued with his life, like it was all a dream for one night.
But there's no problem if the simulation is essentially the matrix. Akira is the one, there is some objective that needs to happen regarding him, and there might be a mixture of real and artificial characters / girls in the simulation with him. The whole thing is a sandbox, complete with love and lust values that the admins / gods can alter. They can load maps, and move actors within the maps. Maybe there's different sandboxes / terminals running at the same time.
If it is a simulation in that sense, we don't know what the actual goal is. So far we're focused on trying to get Akira to heal from his trauma regarding Sekai and how it affects his relationships with women and sex. Nozomu's abuse has given a reason to why he's so protective of Sekai, and we'll see if we learn more about how selfless Sekai actually was (I doubt she was based on how much shit her ghosts want to stir)
But maybe there's an entirely different reason that we haven't even begun to tackle. Maybe he's in here healing his shattered mind while his body is being healed on the outside after jumping to his death, and endgame is rescuing Ami from whatever she did in the wishing well to try and bring him back to life.