When you have students taking out Federal loans, the University getting paid with virtually no risk, and they don't if the student can get a job or pay off the loan, they have no incentive to curb spending. The federal government need to force these universities to take the risk and loan out money directly.
I think the federal government just needs to have a 'fitness standard' for schools to be eligible to receive federal loan dollars. Like, >80% of tuition dollars must be spent on instruction staff, instruction-specific facilities that serve students, students must be able to opt-out of substantial non-instruction services (e.g. dorms, recreational facilities), etc. If you want to build a new building that doesn't have…
However, the cynical reality is that university is as much about signalling competence relative to the rest of the population as it is about learning. Fun fact: Stanford's computer science program is not accredited. The department explained that it's a mountain of paperwork to get accredited and it wouldn't benefit Stanford at all because it's already so prestigious.