The attestation uses a secure enclave in your processor with a secret key you can't access to verify that secure boot is on, you booted a signed OS, the OS is in locked-down mode, etc.
>you can't access
Don't you see how contradictory this is?
No secure enclave of registers or hidden secret keys can help, because a person can utilize the lower-level physical world around the processor to manipulate it (e.g sending electrical currents from a programator device manually). But that is a last resort, there are simple software attacks available already to fake as many "attested" devices as needed (for the same DRM system of Android). It will only bring more jeopardy to the "integrity"
And for tech-minded people it doesn't fundamentally change anything, it just means that it now takes more time to do the same than before