Comment by Borealid

I gave three ways in which encrypting a disk using a TPM provides advantages over encrypting the disk using a secret password.

Encrypting the disk using a secret password provides advantages over encrypting the disk using a public password.

Encrypting the disk using a public password again provides advantages over not encrypting the disk (such as being able to securely "delete" data by removing the data encryption key).

I agree with your core point that attempting to use measured boot and secure boot to control whether the disk can be decrypted is full of holes. But if you want the computer to have an encrypted drive and to be able to boot up without a network or human intervention, what are your options really?