They do not.
The presence of many SSR kamihime is definitely not a cash grab. If they wanted to milk the low drop rate they wouldn't release miracle tickets, which can ignore all the trash SSR and get the right one immediately.
They've taken steps to make sure that teams made of SR and R kamihime are entirely useable. The elements aren't entirely in balance at the moment but most teams can have every single skill they need without a single SSR. Some of the members are in the gem gacha for crying out loud! This game makes money by being a lot of effort, not a lot of luck.