Bewareofserialkillers

i'd call it understated rather than glossed over. the impact of that rape resonates more in the character's emotions and mindsets.

yegyum very much has a reaction to what jooyung did, and actively fucking him harshly was part of that. it's something he does in anger, probably frustration, and with bitterness in reaction to what jooyung did to him. it's not yegyum reciprocating jooyung's feelings, but reciprocating the hurt and violence of jooyung's assault and even their whole arrangement. he's venting his negative emotions and doing what jooyung wants him to do one last time, because that assault is the final straw for yegyum that overrides any lingering sympathy for or loyalty to jooyung. after that incident, yegyum can be final about ending things with jooyung without remorse.

jooin gives up any claim to the family business and hands over leadership/the succession to jooyung, and while it's not a punishment, it's not exactly a reward for jooyung, and jooyung doesn't take it as such, because jooin being in a position to "hand it over" is what jooyung had been striving against the whole time. ultimately, jooin doesn't care about the position, and views it as jooyung's rightful inheritance anyways because of the work he's done for it and acknowledging his mother's treatment of jooyung. so even though it's a net gain for jooyung materially, he's taking emotional and mental damage, and good blow to his ego/pride from jooin giving him a backhanded promotion and yegyum finally rejecting him for good.

both jooin and yegyum aren't cold-hearted bastards, so up until jooyung threatens jooin and jooyung rapes yegyum, they both had some degree of sympathy for him and had things they felt they owed him, jooin because he knew and was a part of jooyung's not-so-stellar home life, yegyum because he was indebted to jooyung, who really did help him out when he needed it (even though it wasn't from the goodness of his heart). so it was difficult to make the clean break they each needed (jooin because of general depression/lethargy, yegyum because he has nothing to fall back on/fight back with) until jooyung wrongs them significantly and they have someone (each other) to fight for.
it was extremely unlikely for jooyung to get any formal punishment due to his status and i don't see yegyum as someone who would fight for that for himself, so it's more of a comeuppance in narrative terms, because jooyung gets nothing that he wanted out of his relationships with jooin/his family (superior status/recognition within the family, causing jooin anguish over his mother as revenge for his own mother) or yegyum (unrequited "love"/obsession). that's what the final confrontation between them conveys - jooyung's defeat.

yegyum's feelings/reaction to being raped are also present - there's his immediate power exchange of sorts when he takes on the active position with jooyung to retaliate, he reflects about it in the pool in the very next chapter and later talks about it with jooin, where he pretty much renounces topping and affirms a preference for bottoming because of it. it's not as involved of a recovery process as what was depicted in ouroboros, but the circumstances of this rape are different, and yegyum's capacity and support in handling it are different. not every victim reacts in the same way

it's understandable if you don't like how things played out, and i would say the ending of this feels rather compressed and truncated, so some room to unpack more of the fallout would have been nice, but saying that the rape was glossed over and treated like in any other bl that handles rape poorly seems unsupported by the text if you're reading closely.

I agree with your messaging and I didn’t think mc reciprocated romantically and got that they sympathize with him but I didn’t like how the rape was portrayed. That’s all

If I remember correctly from the novel, he should have been like 20 or 21 and it was considered coming of age or something. Could be just the translation tho.
Being 18 left kind of bad taste, but even 21 is kinda young