I'm lucky. We got a covered porch with a wall. The wall blocks the view from the street and from a quick glance it looks like the actual porch is small and empty. 🤷🏽
They're definitely supposed to knock. But I don't think I ever noticed that they do either.
When I'm at other people's house I hear them ding the ring doorbell and run. But I don't have that I have a regular doorbell. They never ring and I don't think they knock.
I think they just do electric doorbells because they're loud and record the time with notifications and shit and they know you'll know if they don't.