Both contain time travel/parallel worlds. The storyline is also similar and give off the same vibe.
The dramas are different but for some reason, they have the same vibe. The female leads personalities and the (kinda) love triangles are similar. They both are enjoyable and funny. Even though User Not Found was about students who switch identities and Perfume is about an adult who gets younger, it has the same "pretending to be someone I'm not" storyline
Has a similar storyline. Arthdal chronicles is a little more fantasy but if you enjoyed Kingdom you will defiantly enjoy Arthdal Chronicles.
The plot is a little different since in Dream High they are students and in Idol they are already in a group but it has the saw "fighting to get to the top" storyline.