It is fine to speculate, but "must" is a strong assumption. Your analogy is also based on flawed data. Yes, when riding on streets there is a chance of getting killed, but getting regular exercise reduces your chance of dying for other reasons. There are many studies that demonstrate this. Here is one:

https://www.newscientist.com/article/2237214-why-the-health-...

https://www.bmj.com/content/357/bmj.j1456

Tell me what you think the benefit:risk ratio is of doing jumping jacks at a gun range.

I have worked from home for a long time, but 15+ years ago I commuted by bike about 12 miles each way three times a week when the weather was good. Dominance had nothing to do with my choice to bike there.

I could ride there by bike in 45 minutes, or I could drive there in 25 minutes (lots of stop and go). Same on the return trip. My mental calculus was I got 90 minutes of exercise for an incremental time expense of 40 minutes. That I was also not polluting was a bonus.

The nearest accident I had ever was one day when I was on connector road that had recently been widened and hadn't yet picked up a lot of use. Despite there being no traffic at that moment, I've always 100% obeyed traffic laws, so I stood over my bike waiting for the red light to change. About 20 seconds into it a pickup truck came screeching to a stop just about five feet behind me - he literally locked the tires and left skid marks. Guess what his reaction was: to shout and scream to the point of spitting that I was lucky to be alive and that I wan an asshole for biking on the road. I still don't know if he saw me all along and it was a calculated dominance display, or if he was daydreaming and really did nearly cream me.