We are talking about a level of effort that is less than people's commute or a simple walking of the dog. People exert themselves more than a slow 1-mile jog by vacuuming their house or carrying groceries home from the store.
It doesn't magically turn dangerous just because the activity is labeled "running".
I looked it up and running slowly at a 12 minute per mile pace is about 8 METs, and vacuuming might be around 4 METs so that doesn’t seem to be true.
Also running tends to be more repetitive and pounding on the joints which requires more recovery time than simply vacuuming. I’ve never heard someone get injured vacuuming but I know dozens of people injured from running.
> People exert themselves more than a slow 1-mile jog by vacuuming their house or carrying groceries home from the store.
As someone who vacuums and carries groceries but doesn't run, I find that pretty hard to believe. Maybe if you are a very fit runner? But then those other activities would hopefully also be easier.