nobody ever seems to recognize the benefits of Modularising your grid as well.

Ukraine is an excellent example of why centralizing your grid energy source is a bad plan... but not just for war situations. If you have an agile, adaptable modular grid you can recover for any form of disaster (natural or man made) very quickly and cheaply.

I really feel this is an under valued aspect of electrification and greening of the power sources we use.

This feels a bit like talking in hindsight.

With fossil power plants, the bigger plants were more efficient. This lead to centralization. We now find ourselves in a situation where you can end up with a lot of small/local generation.

What happened in Ukraine can probably happen in almost every developed country today as this was all built/planned in a different time.