Drones are loud, and it can't be avoided (they need to move air to provide lift, and doing so creates vibration - I.e noise). Cars are definitely loud but not on the scale of a swarm of drones.
Drones don't have the cargo capacity of, e.g. a moderately sized van.
We don't have the traffic management policies for low air traffic, and we do have those policies already for street traffic.
Most importantly, deliveries don't account for the majority of traffic: in fact, most commercial deliveries happen at off hours for traffic. If you eliminated deliveries in cities, you may get rid of some annoying double parked Amazon vans, but you wouldn't meaningfully reduce traffic. The majority of traffic is people in personal automobiles (usually one or two per several ton SUV).
We get walkable and safe streets by changing our building codes and parking requirements to make walkable neighborhoods legal to build. And by building useful public transit, at a local and regional level. And by incentivizing personal mobility options like (e-)bikes and scooters, while disinventivizing cars. But delivery vehicles, along with work trucks and vans: I have no problem with them staying exactly as is. If we get rid of the vast majority of personal vehicle traffic, then commercial delivery vans will be no big deal, and small deliveries will happen via ebikes and cargo ebikes. No need for drones!