Maybe this isn't just happening in the area where you live but may have become a common problem around the world. But in your case, the level of addiction of children to online games seem to have crossed the limit so that it interferes with their activities and even behavior.
Of course every game addiction will be very difficult to solve by most people and it requires a process and time with a gentle approach because it is still a child. I don't think you should use violence because that will cause the child to be mentally worse off than the verbal approach. Parents' involvement is needed to reduce children's playing time in online game, meaning that they should ask them to leave the game as often as possible to do other activities.
parents can always find a way how to distract them from playing online games, if they really want to. that is for their kids' future and if they will let them do what they want, they will find it difficult in school. maybe enroll them in martial arts class or swimming lessons, or whatever is applicable around your area, which you may think will give the kid another activity to look forward to. they need other motivation to live in this life.
if they feel, there is no other activity other than playing online games, then, they will always find a way how to access their games.
Depends really on parenting or how they do handle out their kids but honestly this is some sort of unavoidable thing because of what era we are into now where digital is already in our front
which means only a few steps then you can actually deal up with online things or get engagement with it.Parents should lecture out their kids even into young age that playing online games
are really that bad specially on a very long hours.Maybe it would be just enough if they do let for some minutes or an hour but going past beyond that would really
be bad already.