I finally understand what's bothering me with this arc. It's not that Nanako is way over the top (she's actually entertaining in way), no. It's the fact that every other character in this universe has 0 agency, no morals, and tend to be really dumb. The affection points system makes it so that every interaction feels fake, unlike what we had in the various novels. They're not even real characters, just ... yeah, computer programs. Very influenceable and unlikable computer programs. Because of this, it makes me want MC to just leave this world and watch it get destroyed. There's nothing good to retain from it.
Since the 3rd ML has still to make an appearance, I guess that means this will be another painfully long arc ... I miss the earlier arcs. The story just gets more and more different from its original concept (see title).