The true strength of the rope data structure its performance in worst case conditions. Even after a huge series of edits, it recombines leaves and rebalances the tree so it's almost as efficient as when it's loaded freshly. It's not like a piece table, which is amazingly efficient at first and then fragments.

[The actual analysis is much more subtle, as the tree invariants are a minimum and maximum number of children for non-root non-leaf nodes, and a minimum and maximum leaf size. When freshly loaded, the code is careful to maximally pack both, and after extensive editing the distribution will be more varied. However, it's still rigorously O(log n), so it ends up being a small constant factor. Might be worth doing some empirical performance testing.]