Well, it is mentioned at the top of the Multifactor Authentication recommendation page that hardware security keys have their own category.
That being said… (and this could be worth a dedicated thread if required)
I think that Token2 deserves a spot in the list. They’re Swiss-made, and their PIN+ Release 3 allows up to 300 FIDO2.1 Resident Keys + 50 TOTP/HOTP + 1 HOTP via HID. Basically, way more than most the YubiKeys available today. The latest firmware update from Yubico allows up to 64 OATP/TOTP on the Serie 5s tho.
Going back to the Token2, they’re not as tough as the YubiKeys (mostly made of glued plastic), they’re not IP rated either, but the PCB inside has a coating for “enhanced water resistance”. And their price is cannot be compared to the YubiKeys.
It’s also worth mentioning that more and more hardware crypto wallets are FIDO2 compliant, like the Trezor 3 and 5. Even the Trezor Model One is FIDO U2F compliant. At this point
I think that the Security Keys recommendations could benefit from a nice refresh.
Yubico is still the king, and there’s no argument about that. But a few solid options have appeared on the market. Some that could be a great backup option, others that could be better for the daily life. (One solid YubiKey on the go, anywhere. One other key, not necessarily from Yubico, at home.)