⬆️ But don’t they emphasize social distancing outside as well? Me and this guy were definitely not 6 feet apart.
Here we're talking about vehicles for the virus - which itself is microscopic and can easily penetrate any mask.
First: the most common form of spread is tactile, especially via fecal matter - hand washing after using the bathroom is the most important preventative measure to protect yourself & others.
(I recommend also frequent face washing around eyes, nose & mouth, and increased oral hygiene - using an alcohol-based mouthwash regularly, brushing teeth, using saline solution on nasal passages and hydrogen peroxide on a cotton swab to clean the ears - basically keeping all the orifices of the head; the entry routes for virus, clean!)
The second most common form of spread is from aerosols produced by the body: Sneezes are bad as they are so powerful they can project over 15 feet and create aerosols that can linger in the air and masks will only stop the solid droplets created by them, but not the aerosols.
The third & least common form of spread is from droplets (which can be saliva or mucous expelled from the body): Droplets are pulled by gravity to the ground within a couple feet of their exit point, but aerosols can linger in the air (aerosols from humans are generally produced through sneezes or a very strong cough).
There's really no protection from aerosols whether you wear a mask or not - thus distancing is one way to protect from aerosols - hoping air currents dissipate the breath of one person before it reaches another.
Outdoors, distancing is less important than indoors - again, due to wind & air currents that don't exist indoors. But to be safe, I'd stick with staying 6 feet apart from people outdoors and even further if possible indoors.
If someone is about to sneeze or coughing in your direction, whether indoors or out, it's best to get far away from them and best for them (or you if you feel a cough or sneeze coming on) to move away from others and try to cover your mouth and nose with something, be it a hand, hankie, tissue or preferably an elbow, even when wearing a mask (again, masks will stop the droplets you spew out but not the aerosols), move away from people, cough or sneeze in a direction away from others, and, if inside, run to a door or window to cough or sneeze outside.
Just for the record, I've had multiple encounters as you described with people and their dogs outdoors since the start of the pandemic and I've never worn a mask while taking a walk or walking my neighbor's dog. I always ask the dog owners' permission if I can pet their dog, but have also stood outside; talking & petting for lengthy periods of time. Neither I, nor any of the locals or any of their dogs I've petted - or my neighbor's dog which the locals have petted - have become seriously ill and I still see & talk to those same people today.