Why is QQ Westward Journey very similar to Tianxia II?

They are all made in China. Now the upgrade mode of domestic online games is similar. Especially when they brush the experience FB, it drives me crazy. However, the pet system of Westward Journey is not bad, but why do I think the pet system imitates the legend of ghosts and gods? Westward Journey is like a hodgepodge, and all the games have similarities.