I agree all things being equal. But they're not. The delivery guy or mailman or building super could infect them too.

It's a hard problem that I struggle with personally. My parents are elderly and not in great health. I live in fear every day that the efforts of my family and their support network (visiting nurses, etc) to help them can kill them.

You are way more likely to get it from someone you know than a stranger. 80% of Wuhan infections were in 'familial clusters'.