I'm 42 and considered beautiful by many people and I can objectively see it too. Through the years, many, many people have told me and I've also been told I'm 'stunning' and 'striking'. I've never been short of admirers.
Looking back, i was always pretty in my teens and twenties but something happened as I got older and I look better now. I think my face has became more angular, my hair and make up look better as I knew what I suited and I have finally perfected my make up style. I also have so much more confidence in myself as a holistic, whole person and I don't need validation from others based on how I look.
I see style and beauty as a bit of fun and it doesn't define me in any way. I don't feel like I'm in competition with anyone, I don't automatically assume youmg women in their 20s are more attractive than me by Virtue of their age either and generally am in a sweet spot where its nice to have them, but I've got more going for me that just my looks.
I think the subtext of the OP is that beautiful women only have beauty and once that starts to go, there is nothing left. Beautiful people can also have many layers to their character; be intelligent, have hobbies, interests, talents, careers, academic studies, a spiritual life, relationships with family and friends, relationship with God, or a million and one other substantial and meaningful aspects to their character which mean they'll be just fine if their beauty fades.
So ageing is not difficult for me. I've still got it, more than I had before even, and if I didn't have it, I'd still be OK.