The energy grid is fundamentally a battery, it would be asinine to have distributed battery sources storing energy for individual units when literally everybody is connected by a giant battery. The fact that it's not super profitable to store energy isn't a failure of the energy system, but the economic system that the grid must adhere to.

Almost all PV is connected to the grid, there's no point in having a battery unless you're totally off the electric grid, in which case obviously you need more infrastructure, like a backup generator, than what you'd need in a regular PV installment.