Hierarchy v.s Relational

Who one is the best? None, you manage your needs. For a mom-pop store ( food/restaurants) can very effectively managed with a large table in a spread-sheet or Access VBAs , avoiding a huge DBMS like SQL-Server, Oracle etc. In the relational database a huge and multiple tables can be divided into smaller tables,  using them in combinations as needed with a tool called "keys". 

Generalized Access Method (GUAM), it is a prism arrangement with a top level access options. Each level the access will split into this and that option. A pointer will access to the right page. What I am afraid of, data duplication, redundancy and you need a middle ware to handle it. (Link to the Business cases). One point this Hierarchical system used in 1969,by North American Rockwell company, to manage a project that sent the mankind to the moon 

Modern DB's used by the all commercial giants.