They're mixing the two to attempt to make a point. "Post-scarcity" is an economic concept, and I've never heard that term used in physics.

There's no point about talking about the physics of the grid without the economics.

The story of the New York blackouts is not one of groundbreaking physics.

It's the story of two lightning strikes, some very basic physics, and a systemic failure.

Understanding the systemic failure is not a physics question. Electricity is already well understood and that physics isn't changing.

A renewable grid is not a physics question either. It's one of regulation, redundancies and the end goal hasn't changed.

Saying "production and consumption on the grid must match" might as well be put in the pile with statements like "wires must be made of conductive material". They're just 2 things that haven't changed.