The advantage of at-scale lithium is the technology advances will trickle down to home users. I have a 30kWh home battery that was about $6k installed and retrofitted (AC coupled, ick I know) into my 12 kW solar system. This is battery slimline and about the size of two suitcases (it's two 15kWh stacks linked together). It charges in full by 12 noon on sunny days (with me then actively sending power back to the grid) and usually by end of day on overcast days.
If it was cheaper, but:
- required 2x as much charging (meaning i would rarely fill it, or needed double the solar)
- was several times as large
I would likely not consider it.
Any tech making home batteries cheaper/longer lifespan/denser is a win for people like me.