I was gonna ask about the biometrics part in a separate question, but its both about security, so might as well combine it in one post.
Okay so I don’t use password managers. I just try to make easy to remember passwords 3-4 random words + 3-4 random numbers. Online accounts can’t be brute forced anyways. For offline accounts, I just increase the words and numbers. For mobile I don’t use biometrics, although I’ve been testing whether or not I want a pin + no biometrics or alphanumeric password + biometrics. I just can’t decide.
Sure, probably they won’t use it for bad purposes.
But there’s nothing saying they won’t use them in any way they see fit.
Maybe they could find a way to find monetize without disclosing them and anonymized, like statistics or with the update in their policy about training their models with whatever information they can get.
Maybe you have an ad blocker and AdSense can’t build a profile from you, but the google already know what sites you were interested enough to make an account and could try to advertise in other ways.
And then the biggest issue: there’s no mention of encryption, so who knows how they store them and where. Could an attacker read them? How are google employees prevented from reading them?
Also, what’s stored at Google is not only accessible by Google, it’s also typically accessible (probably paid for) by intelligence agencies and law enforcement. The Snowden revelations showed that. Same is true for every other big tech company. Even if you think that’s still not a problem because you’re not doing anything wrong, it could be a problem if you’re ever falsely accused of a crime. There are innocent people being thrown into jail for life. Our systems aren’t perfect, so don’t assume nothing will ever happen to you. Also, if you should find yourself living under a fascist government in the future, they could use your past data to actively target you. This is also not entirely unlikely, because the right-wing is currently quite strong again and who knows what will happen after massive socio-political changes due to climate change and more and more uninhabitable or flooded areas.
Don’t give those data hoarders more of your data voluntarily. Only give them the least amount of data possible. Keep private things as private as possible. Everything else can only have negative consequences for you down the road. And that road could be very long, many years long. Decades, even. The data about you never goes away. Storage is cheap.