I recently attended a talk held by a Cape Town plastic surgeon. During the Q&A session she divulged that you really just need two or three beauty products in your skin care routine.
Sunscreen and Retin-A. Add a mild cleanser and some moisturiser and you are good to go, basically.
A few years ago I was told by a dermatologist that the only, only anti-ageing product you need is sunscreen. You can add whatever you want, do treatments and eat healthily, but ultimately the age of your skin will be determined by your level of sun damage. Genes also play a large role of course in how we age, but the sun is harsh AF.