There's adult content so protecting kids from gambling isn't the only problem. Parent can't let their kids use the net with out restrictions because of harmful content. Gambling's a big problem ppl don't want their kids to learn about it but there isn't a way to monitor the ads they see.
I don't know how many but some probably are when they are valuing the protection of their kids from the adult contents and the other contents that are inappropriate for the kids. The penny that they pay for the subscription monthly is worth it for them and that's why it's a way to protect their kids from such contents. While we can't protect them when they're away from us and when they're going to somewhere else, it's best not to allow them with gadgets outside the house to monitor the activities that they're doing on that gadget.
It's on the parent's responsibility to check their kids once in a while. And for the contents that are being viewing or shown to the gadgets, that's when they should also be protective to their kids. I believe there are surveys that pop for the content viewers to say if they're going to continue looking at those contents and if they're not valuable at all, they are free to say and decline all of the questions asked on those forms. That's one good thing with these platforms, they are asking for what's to be shown to the viewers if they have an algorithm.