Take a look at one of the highest paid YouTubers out there, Ryan's Toy Reviews. Obviously he's not cashing in the $10-15M annual profits. It's his parents. But in doing so, they're securing the 5 year old's future for 3 generations to come. Sure, they probably force him to do videos on days where he's not feeling all too well.. but most days, he's enjoying himself. Doing what he likes.

There are a lot of families that will use their kids for photo-ops (politicians or executives at companies), bring their kids to work in to soften up fellow employees / partners for deals and public perception, and monetize them online with blogs / SMM pages. As long as the kid isn't being abused and doesn't hate what his parents are doing, it's fine. Is it unethical under certain eyes? Sure. But it all depends on the culture and perspective.

With crypto it's the same thing. I haven't personally seen it that much on here as with other industries, but there's a reason kid stuff has generally higher CPM / RPM advertising rates than other industries. I mean let's compare YouTube CPMs for Crypto, Kids, Music and controversial content (swearing, 18+ stuff that can feature violent video games or topics like medical marijuana): CPM (cost per 1K views, regardless of monetized or unmonetized) - Crypto = $3-6 direct through Adsense while external would be $5-25, Kids = $5-12 direct, Music $1-2* (varies highly, for example if VEVO or outside), controversial content $.10-$.6.

Crypto and Kids are 2 of the best industries for monetization. Finance is great but it doesn't have the same hype as both kids stuff and crypto enthusiaists.