I think we're talking about two different things here: the specific demands of cycling, vs. age-related changes in our bodies. (We're also talking about competitive sport, when the OP had to do with participation in mass fun events.)
The top competitors in most sports are much, much younger than the top competitors in cycling. That doesn't mean that cyclists' bodies age more slowly than other athletes', it just means that endurance and strategy are so important in cycling that, to a point, they outweigh incremental declines in reflexes, recovery and strength.
Obviously statistics don't define individual situations. Just as it would be perfectly accurate to say generally that men are stronger than women (by about 20% based on weight-class weight-lifting records), nevertheless probably many of the women on this forum are stronger than most men in our demographic.
Bottom line: we still age. Oh, well! I'm at the point where I'm realizing I just have to deal with it.
Speed comes from what you put behind you. - Judi Ketteler