A cliffhanger ending is often defined as a failure of writing or production, but ending on a solid cliffhanger is often better than tying a ribbon on the story.
Epilogues often feel hamfisted or constrain the story if it is revisited in the future.
“Happily ever after” likewise just feels shallow.
The main character “dying” is often left ambiguous in case they do decide to revisit it later anyway. (John Wick 4 being one of the lamest examples)
Often to avoid a cliffhanger ending shows will contort and rapidly close open story threads when they think they will be canceled.
I would much rather have a story end on the Climax and have it left to my imagination than be left unsatisfied in a myriad of other ways they could end the story.