It is a real shame that in 2019 “vampire power usage” is still an issue. I haven’t found any current research that proves it, but since folks keep some electronics for several years or more (my TV is like a decade old…), the old wasteful draws will continue.
I still contend that once a household has spent a month doing measurements and identifying the big draws and vampires, there is no need, nor significant incremental value, in continuous monitoring. It is a fad that will spin up and then fade away.
During that lifecycle will be a period where electrical utility companies will offer more and more detailed online usage data and even household audit services for outliers - for free; since lowering the overall grid usage is in their long term interest. It has already started with many utility companies offering smart thermostat discounts, and online data, etc., etc.,.