Is it a good idea for me to buy Yubikeys or Titan keys for my personal Google account? My wife's? My childrens'? Will that make it less likely, or more likely, that I eventually get arbitrarily locked out? These are accounts that we use on Windows PCs, Chromebooks, and Android phones. The keys would never leave the house. I think.
I know the phones sorta fulfill this function already, but lost phone = big trouble, right?
Also Google relying on Google for anything important/critical is a bad idea. The internet is full of people complaining that Google deactivated their account for no apparent reason.
I guess I’d recommend enrolling both your phone and a Yubikey as a 2FA.
Yes. Buy the keys with at least one backup key. Treat the backup key(s) as 'critical data' and keep it in a fireproof safe or a safe deposit box. As you add more 2FA to existing accounts, you will need to periodically access this backup key and attach it to those accounts. It's extremely unlikely to be locked-out of your account if you authenticate with U2F key and password.
The chance of lock out is basically 0 at that point. Added bonus is that security key auth don't need most of the heuristics based phishing or credential theft detection applied, as they are provably unphishable. So the sign-in is less likely to be subject to false positives of heuristics.