Well yes, but there is a difference between a signal being accessible on a PCB trace I can see with my eyes, vs it being accessible only on the inside of a 7nm silicon die.
There is a reason why a lot of system integrate the security processor on the same piece of silicon whose state the security processor is meant to protect.
The reason discrete TPMs exist is supposed compliance with crypto standards, and physical protection against key extraction, but they sort of miss the forest before the trees. What matters to users is the protection of their data, not the TPM's secrets, and discrete TPMs arent very good at the former.
There is a reason why a lot of system integrate the security processor on the same piece of silicon whose state the security processor is meant to protect.
The reason discrete TPMs exist is supposed compliance with crypto standards, and physical protection against key extraction, but they sort of miss the forest before the trees. What matters to users is the protection of their data, not the TPM's secrets, and discrete TPMs arent very good at the former.