Just as some additional context, the developers have already confirmed that they are actively improving baby, toddler and child gameplay.
The official development roadmap includes infant traits, expanded interactions for infants and children, improved infant needs, additional newborn appearances, better infant teeth, infant/toddler hairstyles and clothing, and body-proportion options:
https://forum.playinzoi.com/t/topic/8256
Kjun has also explained that infants and toddlers need their own emotion and interaction systems and that the team intends to improve these progressively. A toddler stroller has already been in development as well, although it has apparently been technically difficult because of stairs, collision handling and clipping:
https://forum.playinzoi.com/t/topic/7758
More recently, the developers said they were organising autonomous behaviours and interactions for baby traits, continuing to improve baby appearances and hairstyles, and using a dedicated planner for child and toddler content:
https://forum.playinzoi.com/t/topic/12632
https://forum.playinzoi.com/t/topic/13393
https://forum.playinzoi.com/t/topic/11399
I agree that deeper baby gameplay belongs in a life simulator, and some of the core suggestions here would be very welcome—such as carrying and soothing babies, feeding, bathing, changing diapers, strollers, carriers, milestones and stronger family bonds.
However, I think the proposal becomes too broad when it expands into car-seat safety ratings, detailed diaper-bag inventory management, monthly medical examinations, vaccinations, specialist referrals, counselling, early detection of developmental or learning difficulties, and childhood healthcare influencing future careers and overall life satisfaction.
Those are not simply baby interactions anymore. Together, they would require a parenting simulator, paediatric healthcare system, developmental simulation and inventory-management system. Realism can improve immersion, but reproducing every real-life responsibility individually may create repetitive micromanagement rather than enjoyable gameplay.
It might be more useful to separate the proposal into priorities:
Core baby gameplay: carrying, feeding, changing, bathing, soothing, sleeping, cribs, strollers and family interactions.
Development: milestones, traits, learning to crawl or walk, preferences and emotional bonds.
Optional or simplified systems: healthcare appointments, supplies and travel preparation.
Since the developers are already working on many of the foundational baby improvements, perhaps the post could focus more clearly on the specific additions that have not already been announced