Unless you're Usain Bolt, you probably ain't jogging or walking at bicycle speeds.

At bicycle speeds?

15-35 kmph for recreational usage. It's sprinting speeds for people who walk.

It’s very hard to fall on your head at 10 mph or greater when jogging

If you cycle a lot, you're almost guaranteed to crash at some point. Falling from walking or jogging is extremely unlikely. You also have much better chance of blocking the fall with your arms, as they're not on a handlebar, but rather already balancing your body.

Many walkers and joggers wear a lit up harness (or even bicycle lights) to improve their visibility while walking after dark in my area. So yes, some wear safety gear.

When did anyone fall off a walk or a jog?

Every single winter lots of people fall when walking or jogging.

When was the last time you've been outside?

How often do people fall off of bicycles?