I think a great article could be written on how much of the gaming industry, including PC games, phone games and twitch streamers are funded by whales without self control, who are mainly children and teens.
Seems to me freedom of choice isn't just about selecting between good decisions, but having the right to make bad ones. Freedom isn't merely the choice between 'Fresh Stripe' toothpaste and 'Total Whitening' toothpaste - it's having the choice to go without even though it's dumb to have your teeth fall out.
Any society willing to ban lootboxes for informed, consenting, mentally competent adults would have no problem with banning porn and smoking and drinking too much and bicycling without a helmet by following the same logic.
There are steps you could take short of a total ban, of course - as we do for other vices.
This includes hard drugs (smoking and alcohol get a pass primarily due to a pre-existing legacy userbase and industry, but they wouldn't even sort of get that today, anywhere, in a fresh slate, especially nicotine), unsafe practices on the road (such as not wearing a seat belt), and indeed porn where consent is not explicit and informed (revenge porn and child abuse).
And you'll note a lot of economic practices are banned in the Land Of The Free(tm), Ponzi schemes being a good example. Is this unreasonable? If you're a libertarian you might argue it is, but most people think it's a perfectly fine thing to ban.
Not saying you're wrong (although I personally would like to see some of the more exploitative practices in the games industry banned), but you are way off.
Yup, there are strict regulations with regard to gambling because of its addictive nature and, let's not kid ourselves, loot boxes are an uncomfortably close analogue of gambling. I would be very much okay with putting lootbox, particularly gacha games, under similar heavy regulation.