Career prospects for a Math PhD student in pure math?
Given the current market for academic math researchers, I'd encourage everyone in math to make serious plans for an alternative career that you'd be happy with.  Even for most people who end up with tenured positions, it's not clear until well after graduation whether that path is likely to work out, so even the strongest students should be considering other options.  In math the main alternative tracks are data or coding focused industry jobs in finance or tech, or teaching-focused academic positions.  In both cases, these job markets are competitive and they're not looking for people whose main qualification is that they didn't get a research position.  If your alternative option is getting a job in industry, you should already be learning to code and trying to get relevant experience, while if your alternative option is getting a teaching-focused job, you should already be looking for teaching opportunities that will make you stand out as an attractive candidate at teaching-focused institutions.  (In the US those are often small liberal arts colleges, but in Australia I'm not sure how many teaching-focused jobs exist.)

The good news is that there's lots of good jobs for math PhDs out there (much better than many fields), but you won't just stumble into them you need to develop relevant skills and experience.