If I become a parent, of course I will not let my child get to know gambling or others first before earning their own money, I will not show that I also play gambling in front of my child or even I allow it with reasonableness in the future in the child's growth period.
So theoretically, if your kid at the age of 5 goes outside to sell lemonade, you would then introduce him the world of gambling ?
So everything is just around money. You have so much to learn when you become a parent If you forbit, hide, control everything, then when the kid turns 18, moves out from you to live separate, he will go crazy. Even if it is indeed a range with the ease of information in the media, in my opinion, as a parent it is necessary to limit them with the money they manage, and give money only for school supplies with more limited money rather than excessive, because if giving excessive money to them will make them more money and have many opportunities to use that money with other things including gambling, drugs and other things that are negative for the development of my child.
Your strategy would work only if all parents around would do the same. But that never is going to happen. Also with such limitation, you narrow your kids financial development. Of course the kid could spent money unwise, but he can also try buying and reselling stuff. And if you give money only for school supplies, how can "dreaming of buying" will form in your kids head? Btw your scenario of limiting can even play bad. If you give your kid money for 1 apple, but he wants an apple and a pear, guess where he would get extra money? Might think of stealing.
So this all is about finding a balance in parenting. We not only have to give everything good, positive, teach only what is right. But we also have to let (with an explanation, control and monitor) join the dark side a bit. Just remember, that you can raise an angel or totally saint man. Remember that every light deed has a shadow.