The reason u/ModsAreAIDS is arguing with you on this is that last year, there was a high-profile case in which a juvenile was declared incompetent to stand trial after two armed robberies, and then let go, after which point he shot someone else in the head.

https://www.kare11.com/article/news/investigations/juvenile-justice/kare-11-investigates-legislators-fail-legislative-juvenile-gap-reforms/89-c0b818bf-2f10-420f-bfbd-8eef5d9d32d1

It looks like this is specific to Minnesota law and specific to juveniles:

Since the law requires cases to be suspended – even when they involve violent crimes – judges can’t order juveniles to be held in detention or released under law enforcement. Judges’ hands are also tied in these cases because they have no authority to order children to get treatment to restore them to competence. Even if they did have that power, there are no competency restoration programs in Minnesota tailored to juveniles.

But you might see why others are worried that "ward of the state" isn't as permanent as in your experience, given that it's already happened once.