> Mental health is terrified that someone will do something to harm themselves.

I can understand that but involuntary institutionalization should be implemented only if there's an immediate danger to someone's life.

A currently euthymic person mentioning casually there were times they wished they were dead is not cause for institutionalization.

A depressed person who not only thinks about taking their own life but has made plans for it and has the means to execute that plan is in great danger and in need of immediate help.

I think we are seeing literal survivorship bias here where the person whose texts were taken too seriously is alive to tell their tale and everyone whose weren't successfully committed suicide.