They weren't talking about supplying energy with batteries.

The initial use case for small batteries on grids are providing the grid stability, frequency control, (synthetic) inertia and other important operational factors that the original comment thinks are being ignored.

> Unfortunately this is article fails to talk about grid stability, frequency control, inertia, and other important operational factors that keep transmission grids running.

This 'value stacking', which the immediate parent called 'aux services' makes them much more valuable to the grid than just their delivery of power would suggest.

Though we're now approaching a point in the mass deployment where the batteries have flooded that market on many grids and there's only actual energy storage left for them to do (and maybe avoid some transmission bottlenecks).

There is an island or two in UK that does that, involves signals in homes to disable various kinds of devices to drop usage whenever capacity falters.