Afaik Apple went above and beyond to make sure their original iPhone fingerprint sensor never leaked the fingerprint to any app or even the OS itself. Android always just did whatever with the print.
If that's the same philosophy now, Apple is definitely better than Google in terms of privacy.
Full disclosure: I own an Android device and no Apple product except an iPod from 2009 or so.
Is it really private though if it's all being collected, encryption and all, to be decrypted at a future date when the technology is available? All data on the net is captured by the NSA and stored at multiple data centers. One's in Utah. No company can really claim privacy if their product touches the internet since all of the pipes are tapped. It's all semantics. Maybe saying "we don't directly..." or "we don't make it easy..." would be more accurate. There is no privacy on the net, period. It's temporary privacy in the immediate present at best. 5 years from now? They might be able to decrypt everything from the last 10 years that they already have stored. It's guaranteed at some point. 6 years ago Snowden also revealed Apple was on board with the data collection. They are lying, and people don't care and go along with the show. https://appleinsider.com/articles/15/01/21/nsa-leaker-edward...
My larger point was about all of the data, not biometrics specifically. Great, your fingerprint never left the device. Everything else does, which is probably way more personal data than just a fingerprint. Your fingerprint really does me no good unless I want to try to frame you for a crime, or want to get into your specific device or other thing that requires biometrics (maybe your work). Your data, I can make use of a lot of if I were criminally inclined. Your credit card numbers, your ssn, your investment accounts, your pics for making false ID's, passwords, or any other data that has ever flowed from your device. You'd have to be pretty sophisticated to be able to make use of someones fingerprints, while basically anyone could use your credit card number. Which is more valuable and larger vector for exploit?
None of the data you describe ever leaves the device unless you opt in to syncing it to iCloud (which is not on by default). The FaceID/Fingerprint never leaves the device and if you don't enable iCloud syncing of the other data off the device the data is unreachable with keys kept on the device.
Its reasonable to think things encrypted today with good methodologies are likely to remain secure forever.
NSA can't change the fundamental laws of the universe. While cryptology and mathematics is constantly advancing, there hasn't been a fundamental breakage of a block cipher in ages, nor has any evidence emerged to suggest the fundamentals of RSA will be broken.
Computing power alone isn't enough to break todays strong cryptography, and its certainly possible that the underlying math is a constant of the universe.
Edit: Not to mention the snowden leaks suggests that the NSA spends most of their effort subverting implementations rather than the fundamental mathematics.
If that's the same philosophy now, Apple is definitely better than Google in terms of privacy.
Full disclosure: I own an Android device and no Apple product except an iPod from 2009 or so.