Kids should not be let off that easy, after all it is their own life they are ruining, so just as they can use those devices to gamble at such an early age, they could also use them to make a quick internet search and see for themselves the effects gambling could have on their young and impressionable eyes, but they do not do it, so they share the responsibility even if their parents were careless, as they have a responsibility towards themselves to try to get the best outcomes they can get for their own sake.
A kid, if not matured yet, doesn't understand much even though they think they do. You will often see kids saying that they know what they are doing and they can manage but they are all just words and they can't manage anything if they get in trouble, they can't even control their minds and emotions if they get into some difficult situation. So you can't say that the kids shouldn't be let off easily because it's their lives and they need to take responsibility.
That is why they are still kids, they are immature but just have that headstrong which will put them into trouble if we allow them to do as they please. That is why we are there, we are to guide them aright and no matter what they feel about the things that are wrong at their age or adult-related, they should never be allowed to do it no matter how they feel. When children are getting to the age of 14-18, they are worse to tame, and if it is not a direct negative impact through the parent, it may be cryptic, which could be tougher to detect as it could be through the environment, friends and many more, children are also very secretive to make the matters worst.
This is why parents/guardians should even be more sensitive and prove smarter than their children/wards to be able to know what they are up to at all times. There is no way they can outsmart the sensitive parents, after all, we tasted the water of this life before them and there is nothing they are doing or trying to do now that we've not done before. Above all, most of these children are not working to earn money for now, so any children who don't work for their money should not be allowed to waste money. Even if you work for the money, you still have to wait until you are mature enough to make a better-informed judgment of your own before engaging in adult-related activities.