My take is that autonomous cars will help parking and perhaps reduce the need for taxis, though that won't help traffic, indeed.

For instance, if my car can drive itself then I no longer need to park it near where I'm going and I no longer need a taxi to drive me to airport/station.

Regarding drone deliveries, the locations where it can be done safely is limited and there may be further legal restrictions if they cause a nuisance. We also need to see the cost, I doubt it will be worthwhile to order one-off small things often.

Emissions are getting irrelevant as EVs take over and electricity is generated by renewables.