Gridscale batteries also have the benefit of being a very good place to reuse tired automobile batteries that otherwise would just be dumped. If we can get batteries that last 10-15 years in an automobile then another 10-15 in a grid scale deployment that's far better than just lasting 15-20 years in an automobile. It also sucks that batteries completely die and have to be disposed of somehow because that's not sustainable at all, but maybe there will be advancements in the future that make that less of a problem