Out of those under 30, I bet there is a huge differebmnce between those between 20-24 and 25-29. It is no secret that women tend to seek people who are slightly older. A few decades earlier, a 20-22y old guys would just date 16-18y old girls and that wouln't be frowned upon nor put them at risk of going to jail.

Naively, you'd think that if demographics break down 50/50 between the sexes, then 60% of men being single means 60% of women are single too. But that's not the case; the article says men in their 20s are single at twice the rate of women in their 20s.

I agree that part of that ~30% difference could be women dating older men. But it could also be women dating each other: this[0] Gallup poll from 2023 found that 27% of Gen Z women identify as lesbian, gay, or bisexual. Gen Z as noted here doesn't perfectly overlap with people in their 20s, but it seems like this could be another (better?) explanation.

[0]: https://news.gallup.com/poll/611864/lgbtq-identification.asp...