I only have a yard gun on me if I forget to take one of my smaller EDCs out of my pocket while I am doing stuff in the yard.
I live in a pretty quiet sprawling neighborhood on a 1/3 acre lot in a small suburban town to a larger city. I don't see many cougars or wolves or packs of feral dogs. We have a few instances of teenagers vandalizing things every once in awhile in the off hours, but carrying a firearm while I mow probably wouldn't solve that short of them potentially seeing one on my hip during the day thus not TPing my house at night
We do get a few wandering dogs from time to time. Most are friendly neighbor dogs that have gotten out for a walk without their owners knowing. None are more than the typical good ol' mutt or popular domestic family breeds (labs, retrievers, terriers of various flavors). No Rots or even big Mastiffs or even large German Shepherds.
Strangers are pretty rare as we are not right off the highway or interstate or near anything someone could pretend to be lost finding as a foot in the door tactic. The next town over did have a few fake contractors try to talk their way in to places to case them for later burglary, but I AM a contractor. So whatever work I had done that I can't do myself is through a network of known peers.
In short, unless I left my lcr or pico in my pocket, I don't see much of a reason (for ME) to consciously pack a pistol while I do yard work. I could see the need for those way out off the beaten path or on acreage with bigger critters, but arming up to push a mower for 30 minutes isn't high on my priority list.
Now, I have been chased by a dog once or twice when I go for a jog. I run before the sun comes up with the aid of a head lamp. My neighborhood is mostly lit by the porch lights of the houses, so illumination isn't great. The dogs that came after me were mostly running for sport and stopped after a couple houses, and I wasn't running at a full tilt to get away. They weren't busting after me over my leisurely 5 or 6 miles an hour. I carry a cheap baton in hand at times for that, but have never needed it.
I always carry when we go for a long walk, though. I feel pretty secure that my several blocks are safe, but when I'm off my turf I don't mind a pistol in my pocket just in case. And, of course, I always answer the door armed.