I’m not an expert on this topic, but I think it comes down to cost and scalability. You have to construct a new project with custom specs for the exact site you’re on, and the permitting for a large environmental change is another drag. For large scale batteries, they all are a somewhat complex power electronic wrapper around mass produced battery cell cans or pouches that can be dropped anywhere. The cost declines of batteries are undeniable and are not stopping anytime soon.