The drama has a very interesting take on the usual male-female lead relationship. It's also a reflection on how we allow technology to guide and take over our lives, even when it comes to love. (spoiler ahead:)
It only makes sense for the male lead to go for Yuk Joo and the female lead to be with Hye Yeong. Love is not only the split-second feeling of heart flutters. It's also long-term companionship through thick and thin.
I am not in the position to judge Jojo's decision that stemmed from unresolved childhood trauma. Maybe she also does not know who she really loves because she triggered the shield. (That's the problem--are we seriously letting an app determine who we like? There is no space for feelings to develop, only silly first-impressions)
Some might think she is toxic and unfair to the male lead, which I guess is true. I still like Jojo, especially after seeing her grow and rediscover her feelings over 2 seasons.
Oddly, I don't feel much for Sun Oh, the male lead. The show focuses on developing Hye Yeong's character. I don't connect with Sun Oh and his motivations. I only see a slightly bratty guy from a wealthy family, who can be imposing and possessive at times. I saw people talking about Hye Yeong breaking the bro code, but they seemed to forget that it was Sun Oh who started it--going after HY's crush and kissing her without her permission (tbh, kinda creepy).
I have been rooting for HY, and I'm glad Jojo chose him. In real life, HY is the type of guy everyone needs.