Challenges in implementing complete binary search trees

We know that performance-wise, a complete binary search tree is the most optimal tree structure for any given number of nodes. Let us go ahead and see why we cannot practically use them to implement a balanced binary search tree. 

Modifications

If we do not have to modify the tree, it will always remain complete and perform best. However, when we try to insert or delete data from the tree, the tree may no longer remain complete, and its performance will degrade.