[nobrains]

Well, it depends on the kind of a learner you are. Some learners prefer to listen to long lectures and some short (and some might prefer interactivities, and others might prefer one-way communication). This is where personalized learning comes in, which is something in its infancy and being explored by academicians and especially companies focused on e-learning delivery. (I work in tech at an online / blended learning higher education institution).

Now this comment by OP (benrbray) and you (wodenokoto) gives me an idea that courses can be designed in a way that the learner can mention how much hands-free time they have to spare now, depending on which the platform can hold off any interactivities / quizzes until then (or something like that), to make the learning process more personalized.

[whimsicalism]

The problem with this "personalized learning" approach is that, outside of MIT OCW, everyone seems to have skipped implementing the normal, long lecture in front of blackboard to watch method straight to interactive laden content.