Is water washing hair dirty?

I've recently (today, actually, about 5 minutes ago) finished browsing youtube of women and men who don't wash their hair, some don't condition either, and use something called water washing.

Water washing is basically lightly rubbing the dead skin off of your scalp and rinsing with warm or hot water. These people do not load up on products like we do, and only use masks or proteins treatments when needed (if I'm slightly off, my bad. I literally learned about this 20min ago). Our natural oils will eventually coat the hair as a natural conditioner. Do some of you do this also? Is it dirty? Not taking sides just curious.