I’m not super familiar with adoption but I’m pretty sure there’s no buying/selling going on. There are costs with adopting a child but those are costs for the process, not the child itself.
And the credit rating one I can certainly get behind but some of it sounds like BS. I’ve never paid interest on credit cards and my rating was good enough to get the best possible rate when I purchased my home. There was quite a significant time between the start of my credit history and the purchasing of my home. At least 15 years. My credit rating hasn’t changed significantly in years though.