Some key insights from the article:
Basically, what they did was to look at how much batteries would be needed in a given area to provide constant power supply at least 97% of the time, and the calculate the costs of that solar+battery setup compared to coal and nuclear.
Firewood from your own forest is the only one and it’s carbon neutral too. This is meant more as a joke but still.
You aren’t wrong, either, but if you start doing the numbers for how much forest per person we need, there isn’t enough land. It is carbon neutral, though.