Test Principle
What you are defining as ‘perfect’ is relative. Hands-free at their time were considered the best or ‘perfect’ because nothing better than them existed at that time. But as technology progressed and our knowledge increased, we made better products and services. So, this is related with time and the knowledge available, it keeps evolving and the inventions keep on improving. This is true about the human/material world.
Darwin theory is specifically about evolving of living organism with random mutation. I am not sure about biological evolution but it seems to me that its not a random mutation. However scientific evolution is not random as they are specifically designed or optimize based on functionalities.