GTA World caters to minors, with rules made specifically for underage players.
GTA World predominantly has players in North America and Europe.
GTA World allows minors to purchase WorldPoints and then lets them convert these to PandaPoints, which can be used to gamble for a lootbox.
With much of western Europe already legislating lootboxes, I find myself unable to open CSGO lootboxes due to this. 
GTA:World's panda boxes or whatever they're called could be compared to lootboxes in other games, which you usually buy with some sort of currency.
Not only that, but you could technically speculate on the Panda Points marketplace. Which is also illegal in several countries for minors including those living in The Netherlands, with exception to explicit permissions granted by parents. 
I'm just confused to how all this even came to be, because this seems like an IRL legal fuckup. Promoting gambling to minors is a massive fuckup.
For the sake of keeping it simple I'm not going to take a deep dive into every gambling law in every country. Wikipedia's page on lootboxes was a start for my journey too.  And just because it's allowed in France for minors to gamble online doesn't mean that a French company can let children in other countries gamble on their platform.