Yes sadly the Hyundai and Kia key fobs of EVs (at least EV9) don’t have the mechanical backup key in the fob anymore. So you need to carry it on your keychain. Don’t leave it in your trunk. If the 12V battery does out you won’t be able to get into the car.
Anecdotally on my Hyundai ionic hybrid from 2018 it does have a mechanical key in the fob, but it is very non-obvious. It’s physically the same piece as the keyring section at the top of the fob. There is a small catch you release to remove the key from the plastic fob body and it slides out the top.
All this to say Hyundai certainly knows how to do this. If they didn’t do it, it is almost certainly a deliberate omission.