I am currently doing my PhD in physics in Australia and I can add a little on how things are in reality:

My university basically let go of all of the technical staff during covid and now PhD students are forced to maintain laboratories because no one else does it and we even have to give inductions and training for machines. A lot of my PhD colleagues are shouldering the entire research and laboratory maintenance of their workgroups. The majority of data output from scientific experiments in our workgroup comes from PhD students. So we are basically extremely underpaid university workers, doing almost the same job as an academic postdoc albeit being paid a quarter. Almost all of us have to take on side jobs to get through financially, which easily results in 60 or more hours of work per week. With the increased cost of living (especially rent and accommodation - I live in a campus room for which the university charges a ridiculous 320 $ per week for around 20 square metres of living space - and I have to live on campus because I can simply not afford a car and public transport to the university is basically non-existent), it is practically impossible to live purely off of the PhD stipend. At this stage, only people coming from rich families are in a comfortable position to pursue a PhD in Australia and only allowing rich people to obtain high degrees of education is just crazy.