It is easy to shit on append in go. The syntax is ugly, it doesn't feel elegant like using .map might. The value in append, like many other things in go, comes down to simplicity by consistency. When your brain wants to add something to a slice, you immediately snap to append. Your brain as a go developer works exactly like ever other go developer and the result is almost any code that you read acting the same way when it comes to adding values to a slice. Simplicity in code comes in many forms.