Is It YOUR Responsibility to Keep the Uninvolved Parent Informed??

What if you are co-parenting with a parent who essentially is not involved in their children's lives at all.

They don't go to parent-teacher conferences, don't help your children with homework, don't go to school events, don't take the kid or kids to practices and they don't show up to games. They're not involved in the medical decisions.

Do you think that it's your responsibility to keep the other parents informed especially if you share joint decision-making or joint custody? Or do you think it's the other parent's role or responsibility to get themselves informed?