I do understand the point that the biometrics are replacing very short pins usually, oftentimes 4 digits only but I dont quite see how that makes the passcodes worse than the biometrics.
I’d say even a 6 digit passcode with a randomized number pad, alongside an emergency wipe pin, would do better than biometrics, which also need to have a passcode setup as backup anyhow.
Maybe you could play out a few scenarios that illustrate your point?