Although yes, it would be easier, I do it to keep myself “sane”.
On one hand, I want to be able to crop and embed the stopping points in a video so I can focus students’ attention on a particular item. If I don’t I find that they watch videos as if they were watching TV for entertainment (not a lot of information gathering just passive watching).
On the other hand, those videos and video clips are usually part of a much larger assignment. By embedding them in formative, I can have them watch a video and then move on to an embedded simulation, reading, writing assignment or whatever. Everything that is being assessed is in one place so just one place to go look at work. (especially since I then have to put those values in to my LMS).