The only scene I'd guess most in this thread would call "sharing" is the rosalind threesome. That's scant material for an entire game about a gentlemen's club.
You are correct "harem snoozefest" isn't entirely accurate, "domination-sadism" snoozefest would be more accurate. The reason I use the term 'harem snoozefest' is because none of the player's decisions actually have much consequence or impact outside from "I will be fukin this girl/I wont be fukn this girl". Sure, that's a reduction of AVNs in general, but intuitively one'd think in this setting there'd be more weighty consequences. It's not like if you pick a wrong choice with Hana she loses ownership to kath and gets gangbanged at the next show, no, half the cast is protected by 'my waifu' plot armor, thus the term.
You know, it really feels like you skipped through the entirety of the game that wasn't a sharing scene. The player doesn't only choose who he wants to fuck or not. You can treat the girls in a variety of ways, from ignoring, to abusing, to befriending, fucking or romancing. There's so many ways the relationships with the love interests can develop in PC, boiling it down to who you wanna fuck/not fuck really isn't coming close.
On top of that, you get to decide which girl wins the exhibitions. What more plot relevant decision power do you want in a game at this stage? Not to mention all of the other club choices where you have to align yourself with one of the three owners/factions. You really think that won't have plot relevance further into the game? What about Killian? Depending on your choices he's a completely different person.
You can decide to help the carnations, exploit them or ignore them.
Serously man, I haven't played a VN with more freedom of choice of how to conduct myself outside of Our Red String, and even that is debatable.
Most VNs only give you the choice between romance/corruption once and afterwards only about the extend, without ever letting them mix. PC doesn't. It allows for both in a more organic relationship dynamic.
Main theme of the game is also not really working in a gentleman's club but more about who the MC decides to become. Plot is mostly to facilitate his development. This is done extremely well.