We can certainly imagine that (e.g. The Diamond Age: Or, a Young Lady's Illustrated Primer by Neal Stephenson is a good example of such a system), however, this

We can certainly imagine that (e.g. The Diamond Age: Or, a Young Lady's Illustrated Primer by Neal Stephenson is a good example of such a system), however, this is not what we are going through now. The currently built systems mess up the pedagogical tools and curricula we have, but do not yet provide an equivalent or better replacement, so at least in the short term it does make learning worse. Also, if someone can use a chatbot for exploring material does not mean that this is a good pedagogical tool for that - one of the functions that grading has in pedagogy is motivation to nudge learners to actually do the work, and that is a valuable function; expecting people to self-motivate for self-guided education will work for some but will completely fail many those learners who most need education.