That is a belter about gravity making electrons flow more efficent. Are your downstairs lights brighter than upstairs? As correctly pointed out, it’s down to cable size mainly. Compound makes a difference, but look at it like a motorway, but for electrons. The more lanes, the better. The better quality lanes, the better. More down to the amount of lanes really though. The more strands of copper (or whatever) the better. Some sales tactics are superb.