Well consider that a normal person going to university and paying a low amount of $1k on living expenses (i.e. equivalence of living on a $12k annual salary), for a four-year university.
Now imagine he has to go to university full time (the fact full-time is rarely upheld says something about the economic difficulty of spending full-time on school). That means you spend all your disposable non-leisure time on school, either going to class or doing readings, homework, research. In other words: not employed.
That means right off the bat for a 4 year university you're spending $48k, while your income is 0. In other words the mere opportunity cost of a 4 year university instead of working full-time, is nearly $50k.
Then add to that the average tuition annually is $9k at a public local university. (private avg is 3x that, and out of state is 2x that. So the $9k figure is below average, basically the average of the cheapest option). Even with a 50% scholarship you're still looking at roughly $20k in tuition for the 4 years. Then add some for books and such, but whatever let's make it $20k. You're now at $70k.
Now imagine that the average student loan interest rate is around 5%, on the average of $70k for 4 years. And then consider that $1k living expenses is relatively low, and $9k tuition isn't atypical.
So we're now getting close to $80k without the rounding errors and we're not living any amazing lifestyle here at $1k a month in living expenses to pay for rent, insurance, food etc, on a 50% scholarship.
The fact that studying full-time actually entails for most people spending part-time on school, and part-time on work, to offset this financial picture a bit, says something about the economic feasibility of simply dedicating years of time to nothing but study. But even then with a part time job making a few hundred bucks (e.g. $10 an hour flipping burgers 2 full days out of 5 working days a week gets you to $160 a week pre-tax extra), a lot of that goes straight into a modest fun lifestyle above your $12k a year expenses, like a spring break, a college trip, or a semester abroad.
Anyway I don't mean to say that $80k is typical, as you said it's much lower, the average nowadays is actually $35k, nothing close to $80k let alone $100-150k. But I think it's important to appreciate that it's just $35k because of concessions, which means for example not going for certain studies cause it'll be way above the average (e.g. medicine at $100k+), or not dedicating yourself to education because you need to spend 2 full days working part-time besides your studies (some of which you simply have to put in the numbers or you'll certainly fail) while not burning out doing this for years in a row.
So I do believe the $35k figure may diminish that the financial burden of college is a lot harder than the number indicates on face value. To exaggerate what I mean with an analogy it's a bit like observing an extremely dangerous area and seeing very little crime and concluding 'the crime rate is low', when underneath it may hide the fact that people stopped going outside, that the city became unliveable because of this and that there's actually huge problem. In the same way I'm seeing in my own environment many of my peers spend more time working than studying, while enrolled, still graduate with tens of thousands in debt, just for the piece of paper but without having had the ability to fully dedicate multiple years to their craft. This obviously isn't the outcome we want, and represents a huge waste.