>>530915170
Inverse kinematics are usually a middle-ware plugin, Genshin and Star Rail have it, just not part of their walk cycles in order to avoid goofiness in animation and also the environment's geometry usually isn't detailed enough for it.

Many stairs in Star rail are actually slopes, a specific stairway outside of the opera house in belabog is actually a bunch of stairs and has weird traversal properties because of it. In genshin it can get weird because of drastic elevation changes.