The issue is intermittence. As a society we decided to continue using electrical equipment even when the sun is not shining and the wind is not blowing.

And a lot of that can simply be solved with a larger grid.

Yes, in a small geographic area, you might run into a situation where the sun isn't shining and the wind isn't blowing. On the other hand, on a global scale, the sun is always shining and the wind is always blowing.

A realistic solution right now are therefore continent-wide grids that combine hydro, solar, wind and pumped hydro storage.