I mean, I guess attestation might have some value, but it feels like moving the goalposts. Under the threat model of a remote attacker who can compromise a normal networked computer, I can't think of an attack that would succeed with a programmable TOTP code generator that would fail if that code generator was not reprogrammable. Can you?

> It would not be an advantage for your front door lock to be infinitely reprogrammable. It’s just a liability.

Er, most door locks are infinitely reprogrammable, because being able to rekey them without having to replace the whole unit is a huge advantage and the liability/disadvantage is minimal (falling under "It rather involved being on the other side of this airtight hatchway" in an unusually almost-literal sense where you have to be inside the house in order to rekey the lock, at which point you could also do anything else).

Sorry, attestation is the goalpost. The community wants certainty that the package was published by a human with authority, and not just by someone who had access to an authority’s private keys. That is what distinguishes attestation from authentication or authorization.