We could deploy 100x the capacity $/Wh with utility-scale farms. Unfortunately we are just completely failing on basic coordination problems like this in the west, every man for himself.
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.
Having a connected grid is a requirement for being able to transfer energy from places with significant amount of renewable energy (solar, wind, hydro) to others. Even if this comes with large losses in transfer it is still a net positive. Especially if you factor in the resulting stability.
Who knows if it takes away an amount that actually matters - however in the short term at least it absolutely makes things better for the individual installing them, which is good.