I do not see a point of smart appliances besides electrical car. 10 KWt-hour battery will cover all the needs to smooth the demand from all home appliances and costs below 1K usd. It will allow also to significantly reduce maximum power that has to be supplied to a house while allow to increase peak consumption while heavy cooking/AC/heating.

At least in the US most of this is still on the research phase but if you can get a standard adopted for all new equipment you can easily adjust these high draw appliances to act as a virtual power plant. It would be a trivial implementation compared to getting batteries in homes.