confusing ending

I feel like the author had an idea "love triangle with twins where one pretends to be the other" and thought until the middle and then didnt know how the later half would go and sorta improvised. I'm probably biased cause I normally don't like overly shy and non-confrontational characters like Seo Woo so I probably got prejudiced against him from the beginning, but I feel like we got cheated. Him changing for the better is very rushed in the end, it doesn't really feel believable or organic. We initially get so much of Jeo Woo's perspective it feels like Seo Woo is an afterthought, then all of a sudden he gets a bunch of smutty scenes in the second season to make up for how much time Jeo Woo had before. Like, we get why Jeo Woo both helps his brother out with his unorthodox plan, but also why he rebels. Seo Woo's reasons, while they make sense, feel more tacked on at the last minute. Like, "oh btw ye he also felt like Jeo Woo had the spotlight most of the time therefore he can't stand to give this up too". Like... why didnt we get this explained more slowly and earlier on..? Even him dying his hair to look more like his brother we learn at the second part, at the beginning it's only implied because we see them as kids but it's not as clear. If it was explained by the beginning we'd have such a more concrete image of Seo Woo, instead he's a background character for most of the beginning, why???

Also what's up with all those storylines from Jeo Woo that got randomly dropped. Like the one about his first love that broke his heart and made him only have superficial intimate relationships, it's very rushed and not properly explained, and the guy he was casually dating who looked like his ex just super easily I guess accepted he's into someone else and only appears twice??? Or how Ohm also looks like his ex a little. None of these end up developed even though they are teased that they will be, I think because the author didn't realize they made people empathize more with Jeo Woo than they should so she should stop delving into his background. His change in character feels a lot more believable and even that one is rushed.

I mean for the love of god I don't get why Ohm would be into only Seo Woo. WHAT MADE HIM SPECIAL OVER JEO WOO? WHATTTTT
THAT THEY WERE BOTH BULLIED??? FORREAL?

I thought initially the way it was written he'd falled in love with both, but I guess we can't have that BOOO TT___TT