The narrative that kids should not do any races or training at young age is garbage. Vast majority of these young phenoms who flame out usually happens from training alone and likely coached by their parent who isn't qualified to do so. The other portion of runners get overbearing parents. Just don't be either. Especially true for young girls. Kids don't want to go run around the block with their parent or even alone. That's boring. Doing with it 50 of your peers and then goofing off after practice is more fun, social. Running is just a bonus.
Just in the Boulder area:
Gouchers have their elementary school kid running XC. Ritz has his elementary school kid running XC. Sam Chalenga has BOTH of his elementary school kids running XC (one is only 4 years old). The youth running groups in that area like Boulder Mountain Warriors do basic base mileage, workouts 2x a week. They've been doing it for many years with success.
In addition, there are massive efforts to get kids interested in Cross Country in Boulder region:
https://www.teamboco.com/#/mountainlionsxcprogram/
Running at a young age with limited bouts (2x a week) and racing can be fun contrary to popular belief.