Summary Analysis (Yes I'm that loser that loves picking apart LOH haha)

So at the end of the day, I’d say all 3 characters got what they deserved. And they all made important realizations by the end:

Haesoo's biggest obstacle was lacking personal agency. He was always caught up in what his mother wanted, what joowon's father wanted, what would be best for joowon's acting career, what was best for society... He never prioritized his OWN wishes and was miserable thinking his love for joowon was wrong. He also thought he was the only one suffering and Joowon had it easy, so he wanted Joowon to suffer too. Joowon told him "dont fall for me & i wont fall for you", so he manipulated Joowon's emotions (making him jealous/angry for his sake) because he didn't know how else to feel “loved”. Him going and telling Joowon how he feels at the hospital was the first time he truly followed his heart, and he was honest to JW without any facade or manipulation. He also apologized in his monologue realizing that he was wrong for being vindictive and wishing Joowon would suffer. He knew he didn't genuinely mean those things, because when Joowon ACTUALLY got hurt, it broke him. Also I have to add about Haesoo & Taku's relationship: Haesoo never cared much for his past flings, but he genuinely felt sorry to Taku. He actually tried his best in their r/s and felt apologetic when he couldnt return Taku's feelings, also signifying haesoo's change in that case.

Meanwhile Joowon: He actually had good intentions as a teenager, thinking that keeping their relationship undefined would "protect" what they had. This carried onto adulthood due to their taboo forever haunting him/them (as he said: he was stuck in the past). He also feared abandonment as he believed haesoo already abandoned him once after the divorce, pushing his idea that their undefined relationship was the best route and Haesoo would leave "if things got too serious". Through their separation, he realized his mistakes regardless of his intentions, and how he really hurt haesoo when he said "dont fall for me". He also knew he had become arrogant in thinking Haesoo would never leave him, just cause Haesoo kept with him for almost 10 years. So Joowon strived to take responsibility for his mistakes. And he faced his own fears realizing: he'd rather get hurt and abandoned by Haesoo than not tell Haesoo he loved him. Because love should be selfless like that. Imo Joowon had the most time of self-reflection and development in this manhwa, going from impulsive and arrogant to mature and braver with his feelings.
Also, both Haesoo and Joowon were consistently driven apart by external pressures that affected their actions (their initial taboo, their parents, joowon's career). So I don't blame the problems in their relationship solely on themselves. But at the end of the day, both of them learned that to make their relationship work: they had to set aside their personal fears/obstacles, and actually prioritize each other.

Finally Taku: he had a history of exes that he toyed around with and manipulated for his photography career and self-interest. He started seeing Haesoo with the same intentions ("i just wanted to see the story he would write when I was gone" / Leo telling Joowon how Taku uses and drops his models). He never planned to catch feelings, so him going from an emotionless robot, to getting hurt like this was the best lesson for him. He now knows you can't manipulate people's emotions and MAKE THEM love you (For instance, taku's quote: "I wanted to burrow inside that void he [jw] left in you. And then I would kick him out in any way I could" ---> he thought he could make haesoo love him, but now realized he cant). He *hopefully* learned that entering relationships with selfish/manipulative intentions, and with someone who loves someone else, is WRONG. Imo Taku had the least on screen development as he's still quite selfish in the recent chapters. His reactions feel realistic, but that doesn’t mean he's a “good” person, and he ADMITS HIMSELF that he’s not a good person in chapter 99. However he is shown to be happy with someone else in the future, so maybe him having good intentions and being less selfish is more so implied. Maybe we’ll see more of his thoughts in the last few chapters, and how he handled his new relationship differently than his relationship with Haesoo...

Anyway I think the endings for all 3 characters made sense, and I hope yall support the authors on the official site if you like their story!