The role of natural selection is not only in screening non-viable individuals. Its driving form preserves not individual signs of the organism, but their entire complex, all combinations of genes inherent in the body. Selection creates adaptations and species, removing populations that are not effective in terms of survival from the gene pool. The result of its action are new types of organisms, new forms of life.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.