For simple structures or situations with low performance needs, yes definitely. But the classic example of a data type for which persistent structures have a h

For simple structures or situations with low performance needs, yes definitely. But the classic example of a data type for which persistent structures have a hard time cutting the mustard is an associative array. With mutability you get hash tables, which I assume need no introduction. With persistent data structures you're generally stuck with some sort of balanced tree that has O(log n) lookup time in the best case, O(log n) insert time (and memory allocations) in the average case, a lot of pointer overhead, and absolutely depressing locality of reference.