Strawman much? Who ever claimed 100% efficiency? ASIC's are 99% efficient at converting electricity to heat and the initial production costs need to be amortized across all units.
I know You love to make up scenarios that simply doesn't exist in reality. You imagined "security holes" with PoS that doesn't exist in reality. You imagined "election costs" with DPoS that doesn't exist in reality. Now you are imagining "space heater", "water heater" that are PoW ASIC machines, that doesn't exist in reality. You know why? because they are horribly expensive, and inefficient to compete with mega mining farms, because as heaters, they can not be turned on all the time, therefore there's no way for them to ever compete with real mining farms in terms of efficiency.
Let's just keep the topic on something that does exist in reality, that is the $500 million PoW expense that is staring Bitcoin holders in the face!