Tuition dollars is one of two things- the degree which is earned or the development of discipline and thought facilitated by the university and it’s agents.
I am not aware of any explicit or implicit contractual guarantees made by a university that each students tuition will result in the awarding of a degree to the contrary, students are often informed that if they fail to perform adequately, their future at the university is in jeopardy and all tuition to that point forfeit.
Likewise, due to the nature of university learning being a wholly individual endeavor, no guarantee of quality of instruction is made. Indeed, many class sections are not taught by professors, tenured or associate, but by TAs and peer instruction. However, the great variance of instructional modes and pedagogical approaches reinforces the idea that learning is an individual endeavor, and the university is unable to guarantee any individual’s effort, dedication, or capacity.
Thus, one pays tuition to the university because it offers a learning means and if particular performance in coursework merits it, a degree or certificate is awarded with the university’s name on it. Tuition is an installment payment which allows access to that process: A process which is different during a pandemic in character (in person vs. virtual) but not so much in nature (i.e. reliance on individual growth and effort).