Is it ok to put a subplot to a story that is never meant to contribute to the development of the main plot?

Question

Is it ok to put a subplot to a story that is never meant to contribute to the development of the main plot? In Game of Thrones season 8, a lot of the subplots that were explored in previous seasons were completely dismissed or ignored. While this is an example that tells you it's a bad thing, is there a good case for doing this? When is it ok to do this and why? Could you provide some examples?

Answer 1

It would depend on how far into the subplot you want to get, and how unrelated it is to the main plot. I realize that is not a perfect answer, but think about it from a reader's perspective. You expect plots to be related as a reader, and if you invest a significant amount of time reading and the subplot does not pay off, it can be frustrating.