The antagonists only appear when fighting the MC and afterwards they are not mentioned in the story until another conflict with the MC at a more powerful cultivation level.
Side characters that you might find important disappear for hundreds of chapters. E.g. Zhong Xiu, who he has looking for a long time is present for ~10 chapters and they separate from each other a few chapters after they promised they won't be apart
Certain abilities are given importance in the beginning/ middle and are simply ignored during the rest of the story. Also some of them lead to you believe that they will be important but are never developed. For example: