The risk absolutely pales in comparison to the privacy benefits (and the risk of abuses by law enforcement, that were already seeing bear out).
In the USA you supposedly have a right against self-incrimination under the 5th Amendment.
I don't see how being asked to provide your private unlock code or password so that the pigs can trawl your phone just fishing for anything incriminating (or just add something incriminating) would be anything other than "self-incrimination". You should have a right to tell them to fuck off, and this has never been tested by the supreme court.
"the constitutional right of a person to refuse to answer questions or otherwise give testimony against himself".
The Supreme Court of the United States has held that "a witness may have a reasonable fear of prosecution and yet be innocent of any wrongdoing. The privilege serves to protect the innocent who otherwise might be ensnared by ambiguous circumstances."
However, the conservative Roberts SC has already indicated their pleasure in weakening this protection - there's a good chance they'd weaken it more, so long as it's for a conservative cause.
Professor James Joseph Duane of the Regent University School of Law argues that the Supreme Court, in a 5–4 decision in Salinas v. Texas,[45] significantly weakened the privilege, saying "your choice to use the Fifth Amendment privilege can be used against you at trial depending exactly how and where you do it."[46]