stream has its disadvantage. If the server has a lot of people downloading from, then you will have a very laggy video. And it will start and stop. Might as well don't watch.
Streaming suppose to be online, depending on what site and on your security settings (or lack of them), some being real nest of virus. Sites come and go over the years. With a downloaded video, no bad surprise, no virus, no need to be online, etc.
I prefer download. That way I don't have to worry about lag. I can put it on a device that does not have internet access. I can download it, keep it and watch it when ever I want because sometimes streaming sites go down.
I saw a lot of WiFi hotspot in china outfield even in chinese McDonalds,but I only test a few and as WillEater said,it works,so I think we don't need to download it.