In Genshin Impact, why are all the characters I play NPCs?

Xu Guang woke up to find himself transported to the world of Genshin Impact, but there was one problem: why were all these characters NPCs?Never mind, business is more important.On the first day, General Thunder was very refreshed, and so was Thor.The next day, the goddess was very refreshed.[Day 3, Kamisato Ayaka is my safe haven!][Day 4, debunking the myth: Not every place where the Grass God's little feet have stepped will grow Padishalan; it didn't grow in my mouth.][Day 5, this one won't stick. Funinna truly lives up to her title of Water Goddess!]【…】[On the thirtieth day, wait a minute, it seems like Thor has become a real person?]