> alas they loaded it onto the standing charge that is a flat rate per day for having a supply.
Not true, source: my electricity bill. A standing charge exists, but the vast majority of what we pay is per kWh.
The part that you misunderstood, I think, is that the EEG is fixed per kWh and not per euro paid (just like most of our fuel taxes, even if crude doubles or halves in price our price at the pump only shifts a little). The article was quite misunderstable, bordering on wrong even, in that part because it reads as if market rate had any influence on German electricity bills and only the EEG charge was fixed. In reality, it's impossible for a households to get a contract that follows market rate, you always pay the same per kWh no matter if it's Sunday or Monday, windy or calm. The electricity spot market price is only relevant for utilities and for a few heavy industrial users with special contracts (the kind of heavy use where you'd be mandated to give the utility a heads up before increasing or dropping the load).
This will have to change eventually, because load shift is so much mow efficient than storage, but it's difficult to implement because you can't really have both constant rate and variable rate in parallel due to an abundance of bad actors who would have both and ruin the pricing models by opportunistically switching between them.