Essentially, the criteria you are assessed on when applying for university applies to you as a domestic applicant, as well as to your domestic peers who are also applying. Common examples of such criteria include ATAR, as well as year 11 and year 12 marks depending on the university and the scheme. The applications of international students are assessed according to different criteria, meaning you are not directly competing with them for an offer into your desired degree but rather with domestic applicants who are assessed according to the same criteria as you.
That said, a lower number of international students (which seems to have been the case throughout the COVID-19 pandemic) may likely increase your chance of receiving an offer for your chosen degree(s), possibly due to financial reasons, i.e. universities relying on international students as an important source of funds, which they might need to compensate for during the pandemic. Of course, you will still need to meet general and specific entry requirements in terms of your chosen degree, meaning that this should be your main focus, regardless of how the situation will unfold with respect to international students/enrolments.
I hope this helps!