I like Xianxia because there is actual power progression. Compared to many of the new mangas where characters go to max power in about half a chapter...
Also it is often quite different fantasy and sometimes world building can be truly imaginative and different. Where as lot of others are rather too formulaic.
Yeah, I'm one of those readers who adore world building, I can honestly have cardboard cutout characters so long as the world building is great. Coupled with good progression and honestly I could read for a month solid, I have read for a month solid, it was glorious!
Also it is often quite different fantasy and sometimes world building can be truly imaginative and different. Where as lot of others are rather too formulaic.