This was calculated with 1 billion watts.

The microwave oven comparison was to show a power difference between how little 5 watts is compared to a regular household item.

The laws of physics won't let us focus a beam that tightly over that distance due to its diffraction limit.

Shine a laser at the moon and the beam spot is like 50km wide by the time it reaches it.

Nah, there are wavelengths of microwaves that pass through the atmosphere with extremely minimal losses. Thus minimal atmospheric absorbtion.

You can use longer wavelength microwaves that essentially render the atmosphere transparent in terms of losses. So even a 1gw beam would barely lose anything if the right wavelength is chosen. So it wouldn't affect the atmosphere in any relevant manner.

Just did the math.

A 1 gigawatt, 1km wide beam will output 0.12 watts per centimeter squared (in a vacuum).

So it would be a couple of watts worth of power hitting you in the head at most (5-ish watts) . Hardly a weapon.

Your microwave oven in your kitchen is likely over 1000 watts.

I used to work at Dominos. I am 100% certain these aren't actually going to be used by delivery drivers outside of mega-crunchtimes like the day of the Superbowl. These cars will be for the franchise owners and will probably sit in the store driveway as a form of advertising.

They'll keep making drivers use their own cars.