Doubling the number of bird choppers still won’t let you chop birds when the wind is not blowing.
For example, in Alabama during the day we consume a lot more power in the summer (when it's hot) than we do at night during the summer. More so on weekends (when everybody is home from work and school). But on weekdays a lot of homes consume little power during the day while the family is at work and school, only for power demand to spike in the afternoon when everybody gets home from school and work. This change in the day isn't as much if the couple is retired or working from home. But in the winter the power consumption is more at night to keep the house warm during cold nights.
Then there are occasions, like family holidays. Maybe your home consumes very little because your away, or maybe your home consumes a lot because your extended family is staying at your house.
Then you get into city-wide cycles (daily commuters going to work in the city, making power demand increase at 7:00 AM and decrease at 5:00 PM). Or city-wide occasions. For example, in Alabama during football Saturday, the two largest cities by population for the day are Tuscaloosa and Auburn as football fans spend at least half a day there, vastly increasing power demand at the stadiums and restaurants.
The only way for that all to work all the time is for power to be stable all the time and able to produce at large capacity all the time. Solar and wind don't cut the mustard for grid power.