The YuiKey 5 series now supports FIDO2, FIDO U2F, smart card (PIV), Yubico OTP, OpenPGP, OATH-TOTP, OATH-HOTP and Challenge-Response on a single device. There are four different devices that are part of the line: the YubiKey 5 NFC has a USB-A connection and NFC for mobile. The YubiKey 5 Nano features a low profile USB-A design and stays securely inside your port, while the YubiKey 5C and YubiKey 5C Nano feature a USB-C port.
Previously, the only key with FIDO2 onboard was one that didn't support many other standards. If you're planning on fully ditching passwords in favor of a hardware option, you need a key that works with multiple standards and all of your devices. Now YubiKey can offer that, as well as some assurance that these will be future proof.