Re: It comes down to power supply efficiency
Chas: "...a house full of 8W LED bulbs each chomping 0.5W 24/7 in standby mode..."
Huh? 8 watt LED light bulbs are *universally* installed into fixture with a hard power switch. When you turn off a light bulb, LED or otherwise, it's flippin' OFF.
There's NO SUCH THING as standby mode for a light bulb. At least not at this juncture in history.