Video smackdowns like this do at least highlight differences in OS and such, personally I think there is more validity however comparing android to android rather than apples to oranges.
IOS has always been tremendously optimised, and if you want an iOS device then the only place you will get one is from Apple.
Android on the other hand comes in all shapes and sizes and there is a lot more variety which I think tests like this can highlight where one manufacturer may have benefit in faster ram and storage media whereas other OEM's prioritise ram management and lighter skins and such.
But as for real world scenario, yes no-one is opening apps as fast as this one after the other.
But... Most of us do have more apps open than we realise (contacts, dialer, calendar, notes, settings, camera, gallery, calculator, music player - with just that basic set you are up to 9). So we shouldn't dismiss tests like this completely out of hand. Throw in a couple of extra apps like Facebook, Facebook messenger, Tapatalk and hangouts and you are up to 13 apps. From a real world perspective it's how a device handles and runs with these kind of standard apps that we don't even think about that matters.
As long as the Note 7 performs as well as my S7 & S7e in doing so, I will have no complaints. For me app opening speed is less important and I generally use the same standard apps and have them open or refreshing in the background.
It will be interesting to see a Note 7 snapdragon vs exynos speed test only to see how different SOC's and Samsung's optimisations favour one or the other.
But if tests like this highlight a flaw (I am not saying this test has - I have not even bothered watching it) we should acknowledge / accept it, as no device is perfect. To post articles championing one aspect of a device, whilst dismissing evidence of an area the device isn't so hot in does come across as a double standard.
That all being said and playing devils advocate - I am still more concerned personally about whether I should have gone black instead of blue