I pretty much don't use screen protectors anymore. Even my Galaxy S4 wouldn't scratch this easily. For my Nexus 6P, I just have a Rhinoshield which protects against drops and possible shattering, but the screen on the 6P itself is damn good at preventing scratches. This is 2016, why the hell should we start worrying about easily scratching screens? I would rather have a much better scratch proof screen than shatter proof. Why would you want to spend $850+ on something that looks that nice but can be ruined so easily? Also, the fact that the home button finger print scanner can be damaged and ****ed for use so easily is concerning too. So no, it's not something you forget about, especially with something as big and important as GG screens in phones these days.
I also don't purposely try and scratch my phones with pointed metal picks either, so I'm not sure if that YT video is necessarily accurate either...in day to day use, I just keep my phone in my pocket, keys in the opposite pocket.
http://www.androidauthority.com/corning-responds-samsung-galaxy-note-7-scratch-test-video-711210/
It could be that Corning is trading scratch resistance for drop strength with GG 5...and to be scientific, you have to do better than some guy randomly scratching on the screen, he might not being using the same load force between scratch tests. Corning isn't going to test their scratch resistance like that either, they use instruments that can do uniform load and movements, and you can do hundreds/thousands of cycles.
Sammy, Corning probably are probably considering the most common usage scenarios during testing, plus a few others. Fingers are pretty soft, but can trap dust, and styluses, but those can trap dust as well.
Personally, I think it's all overblown, a) not a real scientific test on YT, and b) no matter what you do, you're going to get scratches - not a miracle that will prevent scratches, just reduce them.