I'm making the assumption that by National Grid, you mean the UK's electricity system operator, with National Grid (private company) being replaced by a NESO (public company).
> had in mind that electricity demand should decrease
Does this mean the speaker wanted demand to decrease? The UK forecasts from the Future Energy Scenarios [1] show demand increasing (see page 21).
> intermittent availability of power.
I'm assuming this was related to demand side response. Page 37 of the Future Energy Scenarios pdf contains an overview of this.
I worked at an EV smart charging start up (Kaluza) between 2019-2022 and my experience doesn't line up with a couple of your points:
> You won't be able to wash your clothes when you feel like
During my time at Kaluza the customer could charge their EV whenever they wanted.
> you will have to adapt to when there is spare power,
The customer set their minimum state-of-charge (0-100%) and we would always have it charged to that amount by a specified time, irrespective of demand. We aimed to charge the customer's EV when demand was low (there are UK markets we can sell this ability to - these markets may have changed since I was there), which would save them money, but meeting the minimum SoC was the most important thing.
> This is just a regression in technological progress
Reducing peak demand reduces the amount of infrastructure you need and makes better use of what you have. IMO it's a good upgrade that makes much better use of the assets on the grid.
Vehicle-to-Grid (or Home) charging takes this up a level by feeding power back to the grid. This "What’s next for Vehicle-to-Everything?" PDF [2] is 4 years old now, but has some good data on V2G and the benefits it brings.
1. https://www.neso.energy/document/364541/download
2. https://info.kaluza.com/hubfs/What%E2%80%99s%20next%20for%20....