Society shouldn't be making those decisions. Look back at examples throughout history and other cultures where women have had forced terminations, forced sterilisations, forced adoptions. Did those societies always get those decisions right? Is this a matter of unquestionable right? No, it isn't.
“Society” isn’t making this decision. The court is based on their authority to protect a vulnerable adult.
Do you think vulnerable adults should not have anyone to have authority to help them with decisions they can’t make due to capacity? Because that is an interesting stance, as someone who knows a few vulnerable adults.