It's all utter nonsense. The problem with the game is that the developer doesn't make the sex scenes "DEEP" AND DOESN't SAVOR THE MOMENT. A sex scene is 2-3 pictures and THAT's IT. I don't feel the reality of what is happening. It's like jerking off to pictures in a magazine.
The amount of CGs is not the issue, IMO. Other VNs make do with the same amount or less. I think it's more the usage of them. They feel a bit perfunctory sometimes, used for moments that are not the biggest deal. Like, did we need all those workout CGs? Though the writing is the bigger reason the story is lacking weight.
I think part of it is lack of proper setup and payoff. This latest update, they spend the whole time building up to "I can't wait to fuck the shit of my wife after he's done." It keeps reminding you, over and over, and then at the very end it doesn't happen. It's not so much that I'm saying the VN needs more reclamation scenes, it's that it's setting up certain expectations and then not delivering on them, which feels narratively unsatisfying.
I think lack of preparation and thought is part of the problem too. We see them wait around before each event, but they don't seem to be using that time to think about the logistics of the things they're doing. Not once have they ever thought of condoms. They don't think too deeply about the people they're doing this with and what they might do if they turn out to do something shitty (and they are absolutely the kind of characters who might, for the coworker and trainer, since they think they're making Amelia cheat and are reveling in it). They don't think about what would happen if the family caught them. They're not thinking about what future they want, whether they wanna have kids or something. Some would say they want reality out of their fiction and the characters shouldn't be thinking about any of this, but without it, the story feels a bit weightless. NTS is only exciting because it's risky and taboo.
Related, Amelia being as open as she is could also be part of the problem. She basically has no limiters, and is seemingly up for absolutely anything at this point. If the MC asked her for a BBC creampie orgy (normally the endgame of these types of stories) at this point I don't think she would turn it down. That's part of the fun with the assertive wife, but her pushing back on nothing makes it kinda dull. At the very least it would be fun to see her push back on the bulls when they're being rude or insulting the husband. That's one of the things that makes Yumi really good. Whenever she's like, shut the fuck up, just put it in, you idiot. Or in the recent netorase play #5, when she tells Jin to GTFO at the end, I think that adds a lot to her personality, and strengthens the sense of why she's doing it and her love for Haru.
Anyway, these are just some thoughts off the top of my head that I've had brewing for a while. It's fine if you don't relate.