I suspect that the electric infrastructure probably is oversubscribed, in the sense that I doubt that everyone on my street could draw 200A each all at the same

I suspect that the electric infrastructure probably is oversubscribed, in the sense that I doubt that everyone on my street could draw 200A each all at the same time and not trip a breaker somewhere upstream. But it's a testament to the way electric utilities are run that we don't notice the oversubscription. If ISPs were run the same way, probably nobody would care, either. It's just that they like to press right up against what customers will bear.