PhD students are typically only paid by the university if they provide labor in the form of being a teaching assistant for undergrads, guiding lab sessions and grading assignments and exams. Alternatively they're paid through their advisor's grants, in which case the student brings in revenue in the form of the large overhead cut the uni takes.
The alternative would be hiring dedicated employees to help with grading and lab sessions, and they won't tolerate the $30k/yr a PhD student does. This would have immediate impacts too, as there's no way a lone professor can keep up with grading for the class sizes in early undergrad.
The alternative would be hiring dedicated employees to help with grading and lab sessions, and they won't tolerate the $30k/yr a PhD student does. This would have immediate impacts too, as there's no way a lone professor can keep up with grading for the class sizes in early undergrad.