It seems to be a catch-22 to me.
Now, we'd be screaming "PEDO" from the rooftops while calling for castration and prison, or even execution. What actually happened, was marrying when you were 13 as a female was the norm. It was OK. She had 4 children.. And if you asked her, had a wonderful life.
But in a fairly short time, social norms went from "Puberty means you're an adult, or darn near one" to 'pushing up the definitions of adulthood up to 21 year olds'. And in this case, the social norms were also backed by loads of well-meaning laws that end up being abhorrent in practice (how dare two 17 year olds sext pictures, but they can have as much sex as they want).
If you didn't learn from 2016, laws and words matter. A lot.
I also doubt it was ever the "norm" in the modern civilized world. A quote from wikipedia [1]:
"In the last decades of the [16th] century the age at marriage had climbed to averages of 25 for women and 27 for men in England..."
1: https://en.wikipedia.org/wiki/Western_European_marriage_patt...