All mathematical functions and properties are just tools for manipulating expressions in a logical manner to derive a useful result.
None are "required" to be used at any time - it is just the convenience of the user. There are often more than one way to solve a particular problem. The sequence may seem more understandable in one form to one person than another. There are recommended and common practices that have developed because of their consistent utility. That is why courses involve a lot of examples for students.
For example, the expression #5(x + 6)# can apply the distributive property to derive #5x + 30#. WHICH form makes it easier for you to obtain the final solution is up to you, not a math rule.
In general, you may use the distributive function whenever there are elements of an expression that are distributed. Some good examples are here: