What good is it to the body if it got the newly mixed DNA sections of the two parents? And what is the benefit to the mind?

Organisms have new signs that will help them quickly adapt to changing conditions of existence, the possibility of survival increases.

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.