Roblox creates an in-game stock market (with robinhood-esque charts!) for cosmetic doodads which they release for up to $10,000 USD "MSRP". Except that MSRP is in-game money so it doesn't seem real. Every time in-game money changes hands, they take 30%...so even if the cosmetic doodad appreciated 15% on the fun-looking chart, the child still loses money on their "investment" after fees. If you cash out your in-game money, their exchange rate again takes 30% vs buying-in.
By the time children are successfully creating games on Roblox, assuming they didn't get sucked into the ubiquitous child-labor scam "companies" that hire these children...they've been lusting over those $5,000 cosmetic items for so long that they spend the money they made on the platform, on the platform.
It's a roach motel for child labor. You can put your labor in, but you can never cash out. The shame spiral is real.