In my opinion...
There are so many things wrong with that method. And although you can't see it in the video I can guarantee you you that the paint texture is so altered by that repair method that it will fit into the sore-thumb category. And especially if it was any other color than white.
Granted, from 10 feet away it probably looks pretty good but you can achieve the 10 foot results with a lot less work than shown here.
My first rule-of-thumb when doing a repair such as this is - Keep the repair area as small as possible, i.e., if the scratch is 1/32" wide when you start, then ideally the repair should be 1/32" wide when finished. The reason... almost any repair is going to be detectable to some degree and the smaller you can keep the repair the less obvious to the eye it will be.
Observing that rule is impossible using the method shown. Every step he performed, starting with the pre paint sanding, increased the size of the repair area. Overfilling the scratch with paint increased it further. Sanding the excess paint increases it yet again.
Then if the scratch is completely filled and leveled with the color as shown, where does the clear-coat go? It will form a mound over the repair, again increasing the size of the repair, that cannot be leveled unless you completely remove all of the clear just applied. So, if you level it completely, then what was the point of the clear-coat to begin with? And if you don't level it completely, you now have a raised area encompassing the entire repair.
Sorry, but I've done a lot of paint touch-ups over the years and from my perspective this video is more of a highlight reel of "what not to do" than a direction of "what to do".