Yubikey 5 can only store 20, which isn't a whole lot better. Are there yet any readily available FIDO devices that can store 100s of resident keys (I have almost 400 logins in bitwarden)?
There's also a nifty app that implements CTAP2 on Android Wear, and basically act like an NFC/Bluetooth security key. If you have an Android Wear and don't think your watch will be hacked and rooted, this could be a useful alternative, especially in places where Google doesn't sell their Titan keys.
The website being breached and the passkey public key being dumped is meaningless. They are more likely to compromise a site’s admin access that can get into user accounts than ever crack public key cryptography or simultaneously acquire all three factors necessary to gain access to my vault. And no matter what I do on my end (except only use sites that take security seriously) can stop that.