You are and are not right. You are right about creams being a waste of money AFTER the aging signs are showing up. Those anti wrinkle creams that promise to erase the aging signs, are a good joke. Only the surgeon can fix it, unfortunately.
Creams are not a waste of money, when we do start taking care of that from young. We manage to reduce the aging with a few years. And use a shit ton of SPF, not only on face, but on neck, bust and hands as well.
I am 26 and I am using a cheaper, but with natural ingredients cream. It's also richer, as is for dry skin. My face is oily, so I use more expensive but better creams there. And I Bioderma SPF Spray when I go out.
Unfortunately, I can feel the wrinkles under my fingers and in the sun they are visible. Some vertical stripes, like a barcode, because I am sleeping with a growning face

)) (English is bad).
And third thing, that have nothing to do with self care, is genes: My mom is 45 and she has had her first wrinkles and grey hairs 2 years ago. The thing is that she doesn't take care of herself, like, using face creams, foundations, etc. So, it's definately genetics, in her case. Also, she never dyed her hair (me neither), so, hopefully, I will be the same by then. My aunt has always been a fancy woman, I have been admiring her creams and cosmetics all my childhood and she still has deep wrinkles now.
So, some are lucky with good genes, others have to work with tratments and surgeries. Wich is not a bad thing, I find plastic surgeries as a form of self care too, as time as we don't overdo it and ruin ourselves.
You make your body and face the way you consider it deserves to look and it's nothing wrong with that.
Bookmarks