The problem, in the United States at least, is that a 'High Voltage Direct Current' (HVDC) national grid would need to be created to support wind and solar. The other problem is creating storage batteries at scale for when it is dark or the wind isn't blowing.

Biden's "Build Back Better" program included funding to 'study' a HVDC national grid. Not to build it, just to study it. The final bill that got through congress stripped this from the bill.

If you use this as an example, wind and solar are a good solution at small scale, but become increasingly difficult at the city or regional scale.