I was recently trying to talk a person online out of marrying someone once the two of them are both 18. It's partly because they're head-over-heels in love with their partner and partly to move out of the US to Canada to escape their trans hostile state. They are trans and their partner helped them through some rough patches. The couple is only now meeting in person for the first time after three years. It was a little frustrating talking to them because I'm a naturally cautious person. My husband and I took about five years from first date to cohabiting to wedding. They honestly sounded like your stereotypical love sick teenager.

I would agree with the general judgement of this cartoon. There's going to be some survivor bias for marriages that worked young. I know a woman who married a man who was in his 50's when she was 18, right out of high school. When he died, she never remarried. But you never hear much about the marriages where an 18-year-old deemed themselves "more mature than those other girls/boys" and it turned into a disaster. They typically don't last that long and no one wants to talk about them much.