Imagine it's 1926 and none of this tech is an issue yet. The police can fingerprint and photograph you at intake, they can't compel speech or violate the 5th.
That's exactly what's being applied here. It's not that the police can do more or less than they could in 1926, it's that your biometrics can do more than they did in 1926. They're just fingerprinting you / photographing you .. using your phone.