Most biometrics aren't easily hidden from your environment, everyone's constantly leaving fingerprints and handprints all over everything, shedding skin cells and other DNA material, face and irises can be easily photographed.
So it's kind of cool that a theoretical biometric could be stable over time and not easily leaked, that could take time to produce. Like some sort of cold storage biometric in the far future once certain biometrics become less useful after they're too easily lifted and replicated with new technology. Sort of like deprecating obsolete cryptographic protocols once they're too easily broken.
There should definitely be a scene in the next James Bond film where he rocks up to a top government facility and the guard hands him a terrycloth robe and directs him to an ultra sleek bathing cubicle
multiple times DNA got transferred between totally unknown people and wrong person got convicted... so more biometrics better.
obsolete cryptographic protocols are many times used as a fallback. some application gets response from malicious actor about not supporting such new crypto, so server falls back to older cipher.. lets say some 100s billion dollar companies use systems which behave like this still in 2025...
So it's kind of cool that a theoretical biometric could be stable over time and not easily leaked, that could take time to produce. Like some sort of cold storage biometric in the far future once certain biometrics become less useful after they're too easily lifted and replicated with new technology. Sort of like deprecating obsolete cryptographic protocols once they're too easily broken.