We don't need to know how to sew our own clothes, but knowing how to mend them is useful. Do we really want to live in a world where we toss out a shirt simply because a button falls off?
We don't need to know how to build a home, but knowing how to fix simple problems is useful. Do we really want to live in a world where we have to call in an electrician every time we trigger a circuit breaker?
We don't need to know how to churn butter, but knowing how to cook is useful. Do we really want to live in a world where we depend upon someone else decides what goes into every meal we eat?
Yes, computers are there to do stuff for us and to save time. We should be exploiting that. On the other hand, we should not be reliant upon it to the point where it interferes with control over our own destinies or the creative process.