Reminder: Yubico doesn't have a monopoly on security keys. Make sure your software/tutorials support the open-source alternatives like OnlyKey and NitroKey.
do any other keys have feature sets on par with yubikeys? last i checked they were ahead by a mile, the others i looked at were just fido2 keys
they also support ed25519 FIDO SSH keys, whereas all the cheapo FIDO keys I've tested only support ecdsa-nistp256, but that's a relatively minor difference.
Nitrokey 3 claims that GPG smart card support is planned in an upcoming firmware update. once that's released I may bite the bullet on shipping costs and order one. 55€ shipping to the US for a 49€ key is cost-prohibitive for the most part.