Well, that's self-selective?

At 29-35, aren't >70% of women already in relationships?

Presumably, the majority of ones that want kids, already have them or are in the process.

Additionally, the apps tend to attract more people in hookup culture. So even from the remaining pool, 33% could be misleading.

Also, whether or not you're in a city / high-cost-of-living area makes a difference. That's less than 50% of the total population (in the US at least).

33% for that age group honestly seems high to me. I'd assume it would be lower.