Why relational approach to data modeling produces database more flexible to change compare to other hierarchical and network data models?

When we go through the data models we can identify that relational database model is naturally scalable and extensible, providing a flexible structure to meet changing requirements and increasing amounts of data when comparing to other data models.This model permits changes to a database structure to be implemented easily without impacting the data or the rest of the database.So it is really easy for the database analysis to make necessary changers in existing database. That's why we can say that relational databases offer structural flexibility for the applications written for those databases are easier to maintain than similar applications written for hierarchical or network databases. That same structural flexibility enables to retrieve combinations of data that may not have anticipated needing at the time of the database's design.In theoretically there is no limit on the number of rows, columns or tables. But in the real world growth and change are limited by the relational database management system and physical computing hardware, and changes may impact external applications designed for a specific database structure.