According to my older female friends finding romantic relationships is getting harder for them.
My older male friends are less and less interested in romance as they report finding sex with no strings attached is getting easier with age.
My older male friends are less and less interested in romance as they report finding sex with no strings attached is getting easier with age.
For older women, the situation is the exact opposite. Their dating pool, which consists of (say) all older men keeps decreasing with age.
That might explain why your older female friends find relationships harder as they age, rather than a decrease in their physical attractiveness. The latter is what many women attribute their situation to, but IMO its just statistics and preferences.
But what's also true is women tend to want to settle down in their early-mid 30s (at least in large American cities, among professional types) and now they become simultaneously more selective. In a sense, women are always the 'choosers' with rare exceptions. Men tend to have wider nets, on average.