Your story is a bit deceptive. I think it is a good story, worth reading but is not a serious discussion about how to correct what is wrong with post secondary education in the U.S. The nations you talk about who provide free post secondary education have schools that are run by the government providing the education and they don't provide everyone a free post secondary education. They provide a free post secondary education to the students who qualify. I bet those countries have citizens with school loan debt because they went to a private school because either they did not qualify for admission to the National Schools or chose a better private school. Do the schools you talk about provide free room and board? Many U.S. students with debt have that debt because they borrowed not only money to cover the costs of school but also to cover their living expenses which likely included things like spring break vacations at resorts and beaches.
The U.S. government has very few Universities and they are free including room and board to those who are accepted but they are military academies.
The U.S. government provides generous grants to the poor. I got a grant that made it possible for me to get a BS degree with manageable debt. Oh, the private university I attended did not have a football stadium. Your distorted reporting of college life focuses on a minority but does highlight a real problem but not the major problem.
The idea that the federal government should pay the tuition for students going to state colleges is just going the raise the cost of tuition at state colleges or require the federal government to more heavily regulate state colleges. The system is broken but you have not suggested anything workable. Oh, my state has this program TOPS (Taylor Opportunity Program for Students) is a program of state scholarships for Louisiana residents who attend either one of the Louisiana Public Colleges and Universities, schools that are a part of the Louisiana Community and Technical College System, Louisiana approved Proprietary and Cosmetology Schools or institutions that are a part of the Louisiana Association of Independent Colleges and Universities.
https://mylosfa.la.gov/students-parents/scholarships-grants/tops/
States are better positioned to fix this problem than the federal government. If you let the federal government muck in this you will have the federal government giving money to rich kids going to Harvard.
TEK