The one that pains me is ovens. They are hugely power hungry and here many models have a very tiny amount of insulation (unless you get a "pyrolitic" model that heats up to 500C to burn the oil off, they have better insulation by requirement of that).
We have no energy rating for ovens, so no real incentive to improve. The vast majority are also installed by builders when the house is built, so consumers never even make a choice in the first place. You can also imagine that also pushes most builders to the bottom end of the market. I'm also still always surprised how expensive ovens can be for how simple they are.
Most of them now also have a fan to run air around the the outside of the unit so it doesn't overheat the cupboard around it (but not all) which is perhaps also a hint at the poor insulation. The cheap builder model I most recently pulled apart had such poor insulation and gaps all around it.
Choice's most recent review has running cost per year ranging from $310 to $651 (this is unfortunately behind a paywall): https://www.choice.com.au/home-and-living/kitchen/ovens/revi...
"The running costs are calculated based on running the oven at 170°C for one hour, three times per week for 10 years at 30c per kWh. Where available, the fan-forced function is used, otherwise, the fan-assist is used. For models without either function, the top and bottom elements (convection or traditional bake) are used."
That's also probably generous since you often run a higher temp and I suspect 200-220C might make a big difference in that cost.
It's a good reason to make use of appliances like air fryers (which despite the name are mostly just ovens), they heat a much smaller space and use a lot less power as a result.
Unfortunately the ever shrinking house makes storing and using such things increasingly difficult. Microwaves are also only 50% effeceient (a surprise I recently learnt).
I know why we don't have it, and energy ratings are partly a proxy for it, but I always wished the average consumer had easy ways to be more informed about trade-offs exactly like this article talks about. You can trade energy effeciency for a slower cycle - that's partly why most washers these days have many different cycle options - you're trading one thing for another - but most of the time they just tell you the name of the situation they are supposedly for without even a hint at maybe how much more or less energy or water or delicacy you are trading off. The same reason product reviews are never clear cut because everyone has different priorities :)