At BYU, 100% of the revenue is coming from people or businesses who willingly parted with their resources. At many schools, subsidies make up huge amount of their operating revenue - some more than half. For example, UCF appears to be in really good shape with $62MM in annual revenue. Then you dive deeper and find out that $28MM of that comes from student fees and direct institutional subsidy. Look at any G5 program with a decent budget and their subsidies will dwarf their ticket sales and donations.

Just click on the individual school at this link and you can find a breakdown of their revenue.