Not specifically, just a gradual decline through the first 64 chapters
Ahh, I haven't gotten that far yet, so I can't say for certain why, but my immediate thought is—chapter titles. Many times, chapter titles themselves are like a form of advertisement. I randomly went through your Act 1 chapters, saw the title "Chapter 28: A Night of Intimacy," and
immediately knew that chapter is gonna see a spike in views. And what do you know? It had 1.3k views, a huge spike between ch. 27 and 29. Then I saw "Chapter 32: A Cat teaching the Wolf how to taste her Prey" and also knew it would see a jump in views. I was right again. Smut readers and their smut-ridden brains, smh...
That is my story x) maybe not too smart though, I'm not the brightest haha. Act 1 has a lot of intimacy in the first 30 chapters, it slowly declines as the story progresses to a more serious focus. But I make sure to keep those romance and smut scenes when it feels natural and not forced. Act 2 has fewer love scenes but they are there.
Yeah, that's what I assumed. Many readers who see the tags "smut" and "harem" probably had their monkey brain activated and are there for the 18+ scenes haha. I know it's likely very discouraging to see that they might be less interested in the plot, but I really hope you don't let that convince you to write smut for the sake of views. In my humble opinion that holds no weight, dumping in smut just for smut just reads like slop or ?. Of course, you are fully within your own right to write anything you'd like. R18 material sells, after all. Just don't feel forced to write it; you can often tell when it's passionless smut written by a passionless author.
As for your friends' feedback... yeesh. So unnecessarily harsh. This is why I personally don't like giving feedback. I'd feel too bad.

The only thing I had in mind was maybe separate the large, chunky paragraphs into smaller ones. Can't say much about the direction and etc. But you were writing slice of life, no? Slice of life sometimes don't need a big, active plot direction. Again, I have yet to read too much so I can't give good advice (nor do I think I'm qualified to, lol). But based on my personal experience, having just finished my own Act 1, I started off pretty slowly for some gradual worldbuilding, character introduction, and illustrating what the normal life was like before introducing a conflict.
I don't really give too much feedback when reading since I'm solely there to have fun and make silly comments, but it looks like you really want some feedback, so if you'd like, I can do my best to jot down some notes as I read?