Sysadmins often need to discover how the performance of an application is affected when the system is under certain types of load. This means that an artificial load must be re-created. It is, of course, possible to install dedicated tools to do this but this option isn’t always desirable or possible.
Every Linux distribution comes with all the tools needed to create load. They are not as configurable as dedicated tools but they will always be present and you already know how to use them.