All of the anime on hianime have a really big quality difference than the actual production.
Like literally I compared some scenes of demon slayer side by side from youtube and on hianime the difference was really big, the youtube one was really really good yk, and ofc demon slayer official release was done in 4k and there isn't a single anime on Hianime that is streamed on 4k (BTW site says that they stream in HD, so that's not the main concern, concern is that 1080p on both platform hianime and youtube have a huge difference, which is something that should be fixed fr!!!)
Same goes with mushokutensi, kaiju no.8 and ig every anime with og animation