@david_chisnall yes, it is also tax-free in Australia. However, 34k post-tax is equivalent to just $38k pre-tax, while median graduate salary in 2024 was $75k for Bachelor degree holders. A big difference! Another financial penalty is no pension (superannuation) contributions during PhD.
Australian postgraduate students receiving a stipend also have limits on how much they can work. When I was a PhD student it was 7 hrs/week. Many (most?) PhD students are working as well as studying.
I did mine at a sweet spot where the stipend slightly outpaced the poverty line and I had a nice top-up from a scholarship (I think I was on ~42 k and felt like a queen). Cost of living has gone through the roof since then, though.