Hang on a tick. This legislation seems to bring digital communications into line with the same long-running requirements law enforcement has met for tapping analog comms, like telephones. Namely, you need a court order: a warrant, signed by a judge, after being presented with varying levels of evidence or probable cause (depending on the invasiveness of the surveillance) by law enforcement. Criminal/civil cases alike.
Why, exactly, is that a problem? It seems eminently reasonable that, in a world that has changed to adopt digital communications, the needs of law enforcement would change as well. Unbreakable encryption is a huge impediment to that.
In short — your iPhone is not a black box. There’s nothing magical about it that defeats or changes how it is protected by the Fourth Amendment. Our society needs strong privacy protections, but within a system that allows for maintaining public safety too.