Not who you are replying too. But a yubikey is not a weak factor.

In fact, it’s not even meaningfully more secure than passkey (as passkey is designed) - passkey is, however, more convenient.

So it’s more ‘one weak factor + (really times) one medium/strong factor’ vs ‘one medium/strong factor’.

Which yes, the first one is better in every way from a security perspective. At least in isolation.

The tricky part is that passkeys for most users are way more convenient, meaning they’ll actually get used more, which means if adopted they’ll likely result in more actual security on average.

Yubikeys work well if you’re paying attention, have a security mindset, don’t lose them, etc. which good luck for your average user.