the US government’s #1 financial asset is debt ... for university education
This isn't quite true.. In addition to the assets in the chart, the governemnt has about 8T in mortgages (out of 15T total outstanding) through several Government Sponsored Enterprises, like Freddie Mac and Ginnie Mae: https://www.federalreserve.gov/econresdata/releases/mortouts...
The only difference is that the government took over the student loan market without creating a GSE to manage it.