I agree. Physical access to the device and its often game over.
Sadly reading off the key is already trivial in some cases as showcased in this recent video by stacksmashing
Since the key has to be sent to the cpu in plain text it can easily be sniffed. If however the TPM is integrated in the cpu its not so easy, but then the os can be manipulated or hacked after boot with known exploits.
If you have a long and secure password for you encryption the absolute only way in is to brute force the key which is significantly harder if not impossible regardless of capital