I think TF2[0] might have been the first on the scene with hats in 2009, and other games followed suit once they saw the success... But many of the games I can think of (Counter Strike for one) were aimed at a somewhat older demographic.
https://www.engadget.com/2019/01/26/fortnite-pve-eliminates-...
Gaming's funding model is SUPER broken. I don't know where or when it went so far off the rails, but at some point people shifted from making massive bets on passion projects to doing a little more marketing/advertising/manipulation to make projects more likely to succeed to full on profit-maximization with little regard for the effects. Ethics hasn't kept up, parenting handbooks haven't, and regulation never stood a chance of keeping up.
Whether it's some of us or all of us to blame, the problem is the same. I'm not hopeful enough to count on some sort of moralistic shift in how things are done across the whole human race or even at the country level but something should probably be done about this. For the same reason people generally agree we shouldn't allow children to do some things before a certain age (where they are likely to have developed enough both physically and mentally to process the ramifications and make a choice), we should probably be preventing manipulation of kids at this level. Look at how Juul swept through high schools (and their marketing campaigns, etc). Things are kind of fucked.
[0]: https://www.epicgames.com/fortnite/en-US/news/loot-unboxing
If Hollywood could have turned movies into pretty skinner-boxes they would have done that a decade ago