This is exactly the qestion I was asking myself. What if the child block needs to be deallocated before the parent block ? What if block dependency is changed

This is exactly the qestion I was asking myself. What if the child block needs to be deallocated before the parent block ? What if block dependency is changed ? These functions are to be used with particular conditions which aren't clearly specified. When the conditions are met then it is a clear benefit to use them. But these add complexity and new pitfalls to inexperienced programmers.