Solarpunk

No we don't need both for everyone. Those that can and want to do full rooftop overproduce significantly for their own needs. Even with significant battery capacity, they can easily supply quite a few neighbors.

The balcony solar still significantly reduces your power demand from the grid. But you're still connected to the grid. There's also winter where solar does basically nothing. It's not every individuals responsibility to be completely self sufficient (even though it would be nice). It's much more efficient to have centralized per generation of any type (water, solar, wind, possibly buffers like battery). That's what we have the grid for. We just need the coal plants to be turned off and replaced with sensible alternatives.

Private solar is nice, and any power you didn't need to transport is also nice. But having reliable and renewable grid is non-negotiable.