I whiped out going downhill in wet conditions.
It can lead to tightness....
Maybe they have worked out how to get the most out of their riding. Like not going areo, etc.
When I was racing marathons I used long rides at a high effort to get the 3-4 hour workouts i could not get running. This was long ago and I was a poor grad student and shoes were poor.
Why are you making assumptions and criticizing them without adequate knowledge of what they are doing and why. The one example where the poster have better knowledge (driving to the ride which is in a low risk area) might clue you in that they are not mindless young guys.
And I was a good enough rider that when foot problems meant that I could not run enough to race marathons I turned to racing on the bike.
Finally, someone mentioned Gwen J maybe about crashing. Bicycling was her biggest component and she had to be good enough that she could make the lead group. A year plus of being the dominant triathlon racer culminating in Olympic Gold means that she need bike conditioning and skills. So what was the risk she was taking?