Mobile games based on "Touhou Project" haven't lasted long

Touhou Project. It's a bullet hell shooter game series created by Team Shanghai Alice, characterized by its very flashy and unique bullet patterns. As a Japanese product, it's highly loved in Japan, and its secondary creations are so active that an enormous number of illustrations, arranged music, games, doujinshi, and more are constantly being produced from this IP. There have been several attempts to enter the mobile game market utilizing this IP. However, the results haven't been very good. Perhaps it's partly because they were made as games for the Japanese domestic market. That's just my opinion. The first attempt was "Touhou Cannonball (a board game type)", followed by others like "Touhou Lost Word (turn-based combat)" and "Touhou Danmaku Kagura (rhythm game)", and these attempts continue even now. Among these three games, only Lost Word has survived. Cannonball's waiting times during gameplay were too boring, and Danmaku Kagura was a game where you could enjoy everything without spending money. (500 characters is too tight..)