I have about 20% of my guild having the same latency issues as in that video.

And honestly it is their ISP, but the issue also does not effect them on anything else they play on. They played numerous games with the guild from over seas and yes they had some latency but not to the extreme of this game. So it is also in part this game.

SE does not deserve all the blame, but there is something not working right. Some people in the US are having the issues as well, it is not only those overseas. People on the west coast there is certain server hub if you are routed over it not sure if it is throttling SE or not but the jumps go from 8-14ms per hop to 80-300ms at the hub and it is not steady so it causes sorta a studded effect on twitch based fights.

I suggest people with latency issues do a trace route and check the latency per hop. If there is 1 killing you... you probably need to invest in a 3rd party service to reduce latency, no other way around it atm.