That is true, but only during GC itself. Refcounting causes these issues every time the reference is copied. For malloc, the benefit with a compacting GC is th

That is true, but only during GC itself. Refcounting causes these issues every time the reference is copied. For malloc, the benefit with a compacting GC is that the free memory will always be in a contiguous segment. Therefore, a malloc operating is similar to a stack allocation in that all you need to do is to move a single pointer. Without a compacting GC, you need to search a tree whenever you want to allocate memory.