Although the posted comments should be interesting in their variety of opinions, few clubs have enough regular members for poll results to be meaningful in any way. Many clubs will possibly not even have representation of certain age groups at all or may have only single members in any particular category. So take apparently indicated poll figures with a LARGE pinch of salt.
At my own club, although the frequent winners are mostly in the 40s age group, the reason for this is simply that the majority of members happen to be in that age group! So that assessment of results is almost inevitable on a purely statistical basis. Having said that, we still get winners from all age groups and it is impossible to draw a meaningful generalisation of ability, potential or actual, on age alone.