BSTs are not good if not balanced
Binary search trees
BST notion
Binary search tree
In computer science, a binary search tree (BST), also called an ordered or sorted binary tree, is a rooted binary tree data structure with the key of each internal node being greater than all the keys in the respective node's left subtree and less than the ones in its right subtree. The time complexity of operations on the binary search tree is directly proportional to the height of the tree.
https://en.wikipedia.org/wiki/Binary_search_tree

Seonglae Cho