Larger drones tend to be more quiet, or at the very least are perceived to be so due to the lower pitch sound made by larger, more slowly rotating propellers.

Helicopters have lower pitch and larger, slower rotating blades as well. They're not quiet, and they've had a lot longer to perfect the blade tech. My block gets about 15 deliveries per day from UPS/USPS/FedEx/Amazon/etc. Have you been near a drone, of any size, taking off and landing? It's quite loud. They're not just going to drop the package from the sky. They're going to be constantly landing and taking off to deliver the package, right near you.

On any given day, for most of the year, there's a good chance that someone in earshot of me is running a lawnmower, a string trimmer, or a leaf blower, all of which are louder than a drone. There's also a guy down the road who regularly leaves his loud diesel truck idling, motorcycles going down the road, and occasional jets flying overhead.

All of this annoys the hell out of me, but no one else seems to care. Certainly not enough to ban any of it.

  a lawnmower, a string trimmer, or a leaf blower

All of these are used in daytime almost exclusively.

We're talking about replacing/supplementing residential delivery trucks, which don't run at night.

>They're going to be constantly landing and taking off to deliver the package, right near you.

For delivery, would using a (possibly guided) parachute be an option sometimes? For example if there is a landing target left in someone's yard.

Helicopters have a large airframe directly under the blades. That is part of the problem with their noise generation.