Well, it could be that the storyline didn't resonate with the audience, or there might have been problems with the cast or budget. But I don't have the definite reason.
Some of the popular ones include 'Solo Leveling' and 'The Beginning After the End'. They have gained a huge fan following for their unique storylines and characters.
You should check out 'The God of High School'. It has intense action and thrilling moments that keep you hooked. The world-building and the fight scenes are top-notch.