I mean… it literally is all there is to it

Well, the requirements I faced were to implement the tree such that nodes were inserted with the standard ordering you would expect. Walking the tree to find the best place to insert them, etc.

Again, that's stupidly easy. Right is bigger, left is smaller.

If the current node is a leaf, insert left if smaller and right if bigger.

If not a leaf nods, run the method recursively on the left it it's smaller, on the right if it's bigger.

If they asked you to write a self-balancing binary tree it's one thing, but there's nothing tricky about writing a normal ordered binary tree.