Some good mysteries keep us in the dark too (Swallow You Whole) and can be very interesting, if done well. The problem with this one is that the intrigue behind the fragmented clues isn't as compelling as the resolution of the relationship tension between Dohu and Juheon.
Especially given that the two somewhat reunited, those plot points don't hold the same "power"(?) anymore. Previously, for example, the threat of knowing Dohu's suffering or true mom would create some major shift in the relationship {mending it). But now that they're together, it just becomes something extra the other needs to know before the story ends. The reveal is just not as interesting or anticipated anymore.
This story honestly had me best when they haven't gotten back together yet. It was like "oo is he gonna find out? dang can't wait for him to realise and run back to him!". If author had sequenced the events well, I think it would have been much better.
A lot of people seemed to be frustrated by the progress of the story, but I feel many mistakenly attributed it to the time skip. I personally enjoyed the time skip because it expanded their relationship and characterization. I don't mind the angst either as long as it's well written.
That said, I do have a problem with the story. I didn't really notice it early on in season 3, but the latest chapter showcased it. I'm not a fan of this vague storytelling that the author has been employing in season 3. Basically, the characters are withholding so much information from the readers, so we ended up with a bunch of conversation that lacked context, making it very hard to follow.
I don't understand why the author chose to write like this. I still enjoyed the characters and the story, but this shouldn't be a mystery story. The author decided to write it like it was one. It's ironic whenever I heard people saying they hated misunderstanding trope, but usually in most stories, misunderstanding trope requires us the reader to be in the know. With this series, we were given only fragmented flashbacks, cryptic conversations, and vague monologues. I often finished the reading the chapter thinking, what are they talking about again?
Like this latest chapter, the author should have just revealed what the characters are talking about, instead of making it a mystery to be revealed in the next chapter. It would probably work better as a cliffhanger as opposed to leaving the readers utterly confused.