YubiKeys are non-upgradable by design. This is occasionally annoying when new standards come out and you need to go buy new keys (which is not something that's gonna happen a lot), but it significantly reduces the attack surface of these devices. They've been pretty good about giving out free replacement keys whenever major flaws have been found, and webauthn is pretty good about remaining backwards-compatible with U2F keys, so I don't think it's something they handled particularly badly.