I'm not a parent, but my sister, and many of my friends, are of the life stage where they have kids under 5. The amount of tracking I see them do, especially in the first year of life, is insane. Is there a medical use for it? Do parents share the data with their pediatricians? If not, what's the point? Since all these apps are free, I assume it all just feeds some giant data science model that helps diaper companies advertise better, or something else utterly annoying like that.

(Then again, I usually use a sleep tracker, and aside from a quick glance in the morning, never ever look at the data again. But I figure baby tracking has a decent amount of overhead, and parents are already overworked and overtired enough as it is...)