Solid clarification and expansion there.
For the sake of expanding on cultural/social differences in other places, here in South Korea, most folks i see on dating apps in their 30s are without kids.
It's in the 30s that most relationships turn serious and get married.
I know two people here who got married in their 20s and had kids. Even the one who got married in their early 20s is open about how she maybe rushed into it.
My time in Canada supports everything you've said, mind you. If I hadn't experienced life here in Korea for so many years, I'd probably wholeheartedly agree without realizing that without knowing where OP lives, it's hard to describe what their potential dating windows are.
Agreed on the UK shows. The IT Crowd, Black Books, etc