Interesting research!
The Australian Government is currently conducting a commission into loot-boxes (microtransactions for chance based items). You can read a number of interesting submissions (including my own) on the topic.
The Australian Government has also reached out to the Netherlands to clarify why they regulated lootboxes in games. Their response states:
Loot boxes could possibly have a negative effect on the objective of preventing addiction as much as possible. The integration of loot boxes into games of skill, without the corresponding suitable addiction prevention measures and provisions, is inconsistent with Dutch gambling policy to limit the negative effects of games of chance as much as possible. This because of the following:
According to our analyses, loot boxes have, on average, an addiction potential between moderate and high. A lot of loot boxes have integral elements that are similar to slot machines. Loot boxes with a higher score are often comparable with blackjack or roulette in terms of addiction potential. Loot boxes with a lower score are comparable with small-scale bingo in terms of addiction potential.
A very large group of minors (75% - 95%) play video games. This group can currently be exposed to loot boxes. The risk of gambling addiction in this group is higher than in other groups.
The integration of loot boxes into games of skill provides a low threshold for playing a game of chance. This integration creates a mixture of games of chance and games of skill in an environment that is comparable, in physical terms, with the low threshold of the hotel and catering industry. Such mixing at these locations was prohibited in the Netherlands in the 1990s to reduce exposure to games of chance and to protect minors.
The Senate report is actually due today, but I haven't seen it yet.
I've done quite a bit of work in this space. To those interested I can share some of my own documentation and resources.