It is inefficient in the grand scheme of things yes. But it is very efficient on the level of the individual home owner, especially if they do not own the building so cannot install solar. It is a good way to cheaply reduce the cost of electricity.

Yes, installing the solar power globally, and getting a globally connected grid would be more efficient in terms of solar panels/kW(h). But alas, that also requires a lot more infrastructure.

In the mean time this can reduce the energy bill for many people. Especially, if tied to a battery. It is not intended to provide independence, for that you need a lot more capacity.