This is called mixing with a VU meter and it can and does work. But be careful here because this approach actually assumes you have the right amount of sub or deep energy in both the kick and the bass sounds.
In my studio where I actually sit and mix the sound is great except that any real deep energy or sub type deep energy is slightly quieter compared to when I get up and stand a little further back. So in this case it would be easy to use this method and set the two levels OK except that both sounds would still have a slight excess of that deep energy. It is not until I move around the room into the spot where it is very audible that I notice it.
So it is important to sometimes to use a HPF set for a steeper slope and just the right cutoff freq in order to tame that excessive deepness on one or both of those sounds. This is more important in my opinion. Once I do this then the kick and/or bass sounds great in both positions and then I know the deep energy is tamed just right. This video totally overlooks that. Once you get that energy balanced just right then this approach works well.