This would make sense for a live stream. But we are talking Netflix movies here. If my network can maintain more bandwidth than needed for 1080p/4k most of the

This would make sense for a live stream. But we are talking Netflix movies here. If my network can maintain more bandwidth than needed for 1080p/4k most of the time (which it can) then there is no reason it should ever fall back to lower quality due to a short blip because you can keep several seconds (or minutes) of buffer. For example I never have this problem on Youtube. Only Netflix.