The short answer is - it doesn't matter at all except ...
to the individual concerned.
It's all about self-perception - not what you look like, but what YOU THINK other people think you look like.
To any right-thinking mature individual, a few wrinkles, a bit of additional weight on the hips, grey hair, and all, make no difference to a woman's attractiveness, but the important thing is how that woman fels when she looks in a mirror. If she is comfortable in her own skin, she won;t mind getting older, and showing the signs. However, almost all woman like to make the best of what they have - hence hair dyes, make-up, nice clothes and so on, and botox / plastic surgery is simply a more extreme reaction to the notion of low self-image.
The same applies to men and baldness - most bald men would wish for hair, most women attracted to them find it a matter of no consequence, or even a positive plus!
It's down to how you feel. And on the basis of a multi-million pound cosmetic surgery industry, a lot of people don't feel that wonderful.