Tell that to anyone who has a kid playing Fortnite. They're either spending money or declining to spend money constantly. Fortnite is free in the sense that it's free to walk into a bar.
I've really enjoyed my 20hrs+ playing fortnite without spending any money through the platform. I'm happy for other people to pay for useless items and subsidise my experience.
pubg also tries to encourage you to buy cosmetic items, and I know that people's kids feel they have to do this.
But I have never paid a dime and I pwn them all the time.
The parents should simply tell their kids no, and to git gud. I am a parent too, this isn't at all a hard thing.