That’s a lot of dramas. I haven’t watched many dramas but a lot of the ones I never finished are on your PTW list.
A Poem a Day - Sucked, didn’t like any character. Side characters were horrible.
Where Stars Land - Watched for Lee Je Hoon (Signal), dropped after idk what was it episode 10 because the characters went dumb and plot went downhill.
Thirty but seventeen - I don’t even remember anything about this because the plot was super slow. Nothing stood out for me but I liked the actors/actresses but the drama bores me. Not really a fan of time skips anyways. It was praised but I didn’t really enjoy it.
Hwayugi (A Korean Odyssey) - my first fantasy drama where there was gods and stuff. I stuck with it for a while but got tired of it when it turned redundant. Plus side was Cha Seung Won, he seems like a cool guy, liked his voice and One, newbie. Overall, gets super boring. I don’t know what the main goal of it was.