"Ask HN: How do you trust that your personal machine is not compromised?"
The pivotal word in this question is "you". If you allow a third party, e.g., Google, Apple, Microsoft, a "Certificate Authority", etc., to decide "trust" on your behalf, then it is the third party that controls "trust", not "you".
A third party can tell "you" that "your personal machine" has or has not been "compromised". The third party can decide who to trust.
However, this is quite different than you deciding who to trust.
Under the trust models promoted by "tech" companies like the ones mentioned above, ultimately "you" are not supposed to be the one deciding trust. They want to do this for you.
Unfortunately, "tech" companies are themselves third parties and they may have commercial interests counter to yours.
The pivotal word in this question is "you". If you allow a third party, e.g., Google, Apple, Microsoft, a "Certificate Authority", etc., to decide "trust" on your behalf, then it is the third party that controls "trust", not "you".
A third party can tell "you" that "your personal machine" has or has not been "compromised". The third party can decide who to trust.
However, this is quite different than you deciding who to trust.
Under the trust models promoted by "tech" companies like the ones mentioned above, ultimately "you" are not supposed to be the one deciding trust. They want to do this for you.
Unfortunately, "tech" companies are themselves third parties and they may have commercial interests counter to yours.