Administrative bloat is real.
And with some knowledge around that - if you google - some is entirely bloat, but more than you might think is new issues (cyberliability / hacking / ransomware / info stealing and all the regulations to try and prevent it) as well as general new regulations. Professors are often poorly placed or just won't spend time securing their IT infrastructure, they often can't help with mental health crisis, potential transportation management/costs (parking, busses, etc), sexual assult, just go down the list of things colleges either by choice or by law take a lot more seriously than they did in like 1960. I don't know when this started, but all the fire alarm tests and inspections cost money and time too. You need special fire department and facilities employees to do them. Same for chemical lab safety - go down the list. And all these support staff add to administrative bloat because you need HR, management, planning, and auditing for all of them. Go back 150 years and it was a lot cheaper case they didn't do any of that, but you get the Curies desks that way too(and dead researchers).
On top of regulations directly on colleges, companies, communities, there's also the ever growing work needed for grantwriting and applying for grants, managing the various funding agencies, contract enforcement work (not just for IP etc, but now for the funding agencies themselves breaking their existing contracts). And if you get rid of all these income streams as too much overhead or if we think it's not defensible, guess what, tuition goes up A LOT to cover what those used to pay for. Or the college doesn't do those things and becomes less competitive than ones that do.
And like so many things in life, it becomes a bit of an expected baseline also.
Just like a lot of people would not accept the lack of features and safety of a 1965 Mustang, even if it was at 1965 prices, a lot of people probably wouldn't accept a gender segregated, no support, only professor and maybe TAs and classes, no computers or internet presence, and nothing else sort of thing at a 4 year + college. Even if it was legal. A little less hyperbolic, the people who do already are going to existing trade schools etc.
Just like all the anti sexual harassment "online trainings" everyone has to take cost money to make or buy, and to track people taking them... but they're basically either legally mandated or leave you with a hell of a lot of liability if you get sued and you didn't bother cause it "wasted money". We can argue if adding random trainings like this is good or bad, but it's the kind of thing that's not specific to colleges, but they need them too.
Given how the cost of tuition has greatly outpaced the general rate of inflation over the past several decade, I would think there could be a lot of ways to bring down the costs of college.
Part of this is that tuition used to be far more subsidized. The cost of EVs didn't jump way over the cost of inflation, the government stopped providing the $7,500 subsidy. I would guess that was a big part from the 1970s-2000ish. The last 25 years it goes back to a lot of what I said above - IT both in terms of computers, internet access, staff to deal with that entirely new huge area, staff to deal with the new online threat landscape since 2015 when colleges started taking ransomware etc seriously... This is huge, but I would question the interest of students in a college run mostly without computers a la 1980 style. I bet many would question the usefulness of the education.
One other thing is the sports and rec centers - these are perhaps less justifiable to some, but they are also sales pitches to the students and parents, and for some colleges bring in a lot of money from fans and alumni donations. I might argue sports should be completely separate from schools in all cases, but that's not the world we're in. I don't even think a college needs a gym, but there are others who'll say exercise should be promoted by the college. And this is the same thing - how holistic do we want college to be?
Finally simple economics - Growing demand for higher education, combined with limited capacity and prolonged time to degree completion .... lets the prices rise.