premise that the harem doesn't interest me.
however, a good boy route, away from temptation, leaves you in the dark about several important steps in history.
I do the most stupid of examples, if you are not "interested" in Zarah, she will not send you a selfie and you will not be able to show it to Jolina (although there remains a 1% doubt for the hair color change)
so it's true that you can play however you want, even as a cloistered monk, but you miss out on a lot of plot elements.
my first route was horny dog enough, now i can choose which route i am interested in, but it is not obvious that a player will carry out several routes