Otherwise, it would be an easy hack to raise your kid’s credit score to open a bunch of credit cards for them at birth, and do just the bare minimum to keep the accounts active.

I think this might actually be a thing that people do (however, kids don't have a credit report til they hit 18):

https://www.chase.com/personal/credit-cards/education/build-credit/how-to-establish-credit-history-for-your-child