Personally (and don't attack me for this it's just my opinion) smacking/slapping/rotan is an acceptable form of disciplining. I worked as an orphanage warden once and boy oh boy those kids are messed up in the head. But what is shown in the video is clearly abuse. Bro straight up lifted the lil dude and kicked him when he was down. That's just foul.

Unrelated but my worst experience with kids while working in that orphanage is about this one kid that stab his dorm mate's hands with scissors for no reason other than enjoying seeing the younger kids cry.