I think lootboxes and child gambling should be the same category if we are talking about steam.

Not so much of an actual gambling imo. All you can know is that you will pull something out of a fixed list. But that is all the gambling part. At least with cases you know for a fact that you going to get something. Actual gambling happens off-site with skins that are traded using bot accounts. These services are actual gambling sites with games and chances to win something or lose everything.

Valve probably can ban skin trading and then we’re done. Also, they probably can ban skin market while at it. But, I bet steam market brings tons of money. And, it is not like they are responsible for children gambling skins out off-site. Also, Valve did made restrictions on gambling. This month Valve has banned skin gambling logos/ads on tournament teams jerseys. And also a restriction that would render your newly purchased skins non-tradable for a week. Drop parental control in the mix - children wouldn’t be able gamble anymore.