I didn’t say child marriage was normal. Its not common, and illegal in many parts of the United States. Nonetheless, the laws for sexual and marital consent where it’s allowed are there for those who consent, and protect those who don’t. If they made the legal age for marriage 21 or even 24 (when parents are no longer required to support their children, it wouldn’t affect most people in the US who are marrying much later or not at all.