If he's been doing serious road biking since that age it's probably not something that he's doing on regular streets. Or, he's not just hopping on a bike and taking a leisurely ride down the street for groceries anyway.
Of course he rides on regular streets, he's French. Seeing an elderly woman riding to the shops or a group of lycra-clad pensioners attacking a mountain pass is perfectly normal there.
It is a peculiarly American belief that bicycles are somehow incompatible with motor vehicles. Cyclists need no special facilities, just sane traffic laws that are actively enforced.
Is it a particularly European belief that Americans are unenlightened savages? I mean, we are, but you don't have to assume it.
The public discourse about cycling in America is dominated by myths, because very few Americans have practical experience of regular cycling. Those who do cycle tend to be self-taught, because of the limited availability of cycle training and the lack of a strong tradition of club cycling. America is having to rebuild a culture of cycling from scratch, for no other reason than the ubiquity of the motorcar.
Some of us do cycle, too. There are miles and miles of good trails running through some cities you wouldn't expect.
Also, more pertinent to Plano, what if you want to replace your car entirely? Grocery stores are still pretty spaced out and you are SoL if you want to get into Dallas proper! The DART is incredibly slow, so that's out, and biking from Plano to a night on the town with your friends is Deep Ellum or Greenville Ave is a tall, dangerous order.
Keep it 214!
That depends on how Asia and Africa see America ;)
Certainly made urban, young, progressive America quite a but more impressive when I visited!
https://en.wikipedia.org/wiki/Robert_Marchand_(cyclist)
Aged 35 he finished seventh in the Grand Prix des Nations in 1946.[3] He returned to cycling in 1978[2] and continued training after his 100th birthday.
My point is that the guy has very clearly been training and seriously cycling for a long time. While you can do it on normal city streets, you are often served better to do that on dedicated bike paths or on the open road.
You can reduce the impact of cars all you want and even make your city bike friendly but that's not going to change your ability to really train. It's not crazy to think that his health benefits are from this elevated level of training and not just leisurely cycling.