This doesn't seem excessive to me tbh? The wuxia and xianxia shows are the ones that often have bittersweet or outright unhappy endings, it's kind of a staple of the genre. Hell even the historical ones often end up pretty bittersweet, it's what's expected of those shows. There are a few that are cute with little angst, but they're not the most common type, and in the 90's and 00's it was unusual to get even that. Angst and blood is the genre must. xD

And idk about the other two in the last three but I know that WoH was an adapted BL, so that would explain the cut off ending in order to skirt censorship, which is shitty but not something those who make these shows can control so I can forgive that. Also given the endings of most C-BL's it's fairly standard without the cut-off ending, most of them have tragic endings to 'justify' the BL nature of the shows.