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.