How do we know that?
It is because some members from our team came from diverse migrant backgrounds ourselves! We went through the challenges and discovered effective ways to leap ahead of other job applicants and stand out to potential employers.
The Australian job market is very unique. Even resumes and cover letters are very different compared to the international job market. Your resume might be impressive in Singapore, Malaysia, India or Hong Kong, but in Australia it may not stand out. Or worse, elements in your resume might even considered offensive in Australia!
Also, you may have more than 10 years working experience in another country with a senior rank, but if you have not worked in an Australian company, that experience may not even be considered useful to the potential employer. (Unless, of course, the vacancy is for an international posting for that company.)
Finally, being a migrant, you might not have the necessary professional network to assist you in your job search.