There is hardware level security used to perform the authentication and holds your biometric data locally. If you get a new phone, you have to re-add your fingerprints. Assuming the hardware security is impenetrable by software, it's safe.

But that's not an assumption we can make any more; the security landscape is very dynamic right now. You cannot be too careful.

We all live with constant risk of whose good reputation will be squandered next for a price. Or that AI will revolutionize hacking. Or that quantum computing will break the security. Or that [insert exporting nation here] modified the chip before it shipped for assembly, circumventing the manufacturers entirely. Never mind all the political factors!

Admittedly, I don't go about my life considering any of this, but I'm not a big privacy hawk either. I gave most of my personal data away as a kid and I go about my life assuming it's already out there. Ignorance is bliss, I suppose, at least so far fingers crossed