Why is college so expensive? Because schools that charge $75k/year get more than 10x the number they can handle to apply to go there. Sure not all are going to be full pay, but basic economic theory basically tells you to charge what the market is willing to pay for the product.
Economics is about scarcity management. I can choose to have a large house, a new BMW, the latest iPhone, or send my kid to private school. If I’d rather have the former, maybe OOS public or in state public. It is a free market and consumers and providers agree on what to pay for something that is of an agreed upon value. If you don’t like the cost of the product, you can always choose not to buy it. It is not a right to go to Harvard. If enough people choose not to pay it, then the provider will have to lower their price to the amount that consumers are willing to pay.
Government funding in research doesn’t pay for undergraduate tuition. It pays for the labs and salaries that support the research that they fund. Sure, there may be some mutual benefit in that maybe some grad student who is helping out on funding also teaches or TA’s a class or two, but the cut in government funding isn’t what is driving education costs up. It is purely an economic equation that is one of the most basic.
Finally, if you want to pay less for education, there are options. The real value of education at Purdue has actually decreased over the last eight years as they have held tuition (and I believe room/board) flat over that time period. So with inflation included, it is actually cheaper to get a great degree today then it was 8 years ago.