First it was the lootboxes that became widespread:
~2010 Steam Team Fortress 2, later Counter Strike
2012 EA's Mass Effect 3
2014 Call of Duty and Battlefield
2016 Overwatch
After that it seemed lootboxes were everywhere. In 2017 there was some backlash for EA's Star Wars game and they removed lootboxes, but it did not change the situation overall.
Then in 2020 western gamers were exposed to gacha mechanics with the release of Genshin Impact, where you "roll" with special currency for weapons and characters that you can't get otherwise. And this currency is either bought with real money or VERY slowly accumulated by playing game. The game is free to play otherwise.
In february this year there was a western release of Lost Ark - MMO ARPG(genre similar to Diablo) that involves probabilistic gear upgrades where you either play weeks to months to fully upgrade it, or drop hundreds to thousands of dollars on upgrade materials, game itself is free to play. It was backed by Amazon and promoted by huge Twitch events.
Both Genshin Impact and Lost Ark have very impressive amount of content, beautiful visuals, music - all while being free to play. Could these games be made and succeed without gambling mechanics? I don't know. My experience with Genshin has been that I got a lot more out of it in terms of fun per money spent than out of most from what I buy on Steam sales - which I play for few hours and forget.
I think the regulations about these kinds of games should at the very least require devs to: - State all the probabilities - Define a guarantee or a "pity": at which attempt will you succeed with 100% probability.
Then for each desired outcome, e.g. fully upgrading weapon, there should be displayed an expected and maximum "price", preferably in real currency. This would at least help the adults to moderate their spending. And as for children, yeah, these games should be 18+, I don't believe a child can handle the urge to spend in these games.