Why are some adults the “kiddo magnet” and others aren’t?

This is not a complaint but my friends and I all have littles under two and whenever we go to a park or play place, kids five and under want to play with us while we are attending to our kiddos. Ergo we end up watching all the kiddos in the area because parents are literally glued to their phone. Is it because we are being active participants in their kind of play? Is it being a woman? My kid doesn’t do this with other adults (since he’s so little) but kids will literally come up and grab my hand to play. I’m a good sport and love kids but also, where are the parents and why don’t they play with their kids?!