What is the problem with this code?

node * insert(node * root, int value) {
     
   if(root==NULL)
   {
       node * temp=new node();
        temp->data=value;
         temp->left=NULL;
             temp->right=NULL;
      root=temp;
           
         
       
   }
   else if(root->data<value)
    
        root->left=insert(root->left,value);   
   
  else if(root->data>=value)
  
      root->right=insert(root->right,value);   
  
   return root;
}