The answer depends on the specific area(s) of business that you are interested in. Business as a field is quite multifaceted and is becoming more so given elements such as technological advancements. Business Studies, especially the HSC course, primarily focuses on four key business functions, being:
- Operations
- Marketing
- Finance
- Human resources
Business Studies provides a general understanding of each of these areas, which includes an ability to apply them in the real world, although to a certain extent. This also constitutes a foundation that can be expanded by studying one or more of these areas at tertiary level. Of course, Business Studies is not treated as assumed knowledge or a prerequisite for university degrees, although taking it and subsequently studying a Bachelor of Business/Commerce (and similar degrees) with a major in one or more of these areas can facilitate your studies, especially at first year level, because you would already be familiar with some concepts, as opposed to having to learn them for the first time.
On the other hand, there are other subjects that also provide an understanding of business and an ability to apply some elements in the real world. An example is Economics. While Business Studies does include a slight economics component, Economics as a subject provides more in-depth insight into this area of business, especially since the subject focuses solely on one area instead of four in the case of Business Studies. Similar to Business Studies, Economics is also not treated as assumed knowledge or a prerequisite for university degrees, although studying it can potentially facilitate part of your studies in a Bachelor of Economics and similar degrees.
I hope this helps!