aJRedi says that the point of the video is to highlight the "hard work [and] detail put into the art-style and areas we tend to just speed through to get to max level." It's a whirlwind tour of older areas as well as new raids, all of it beautifully synched up.
Clearly, some amount of layering went in, rather than running the character through all those actual areas, but it still creates a nice effect. Both the jump and the raids look real to me too, so quite a lot of effort has been spent even outside of the actual video editing time.
As pointed out by Icy-Veins, Redi spent two months putting it together. As they put it, "yes, it was the biggest pain in the arse when you realize you missed a clip and it was right in the middle of the video." Worth the effort, I think.