This isn't about the privacy of one individual human. This is about the security practices of a politically exposed person and the information they have access to.
Any high profile, high security clearance individual must have top-notch security. Any information gleaned or stolen from them can have enormous repercussions.
It also creates a scenario where people remain on the bench long after their competence has likely faded. RBG, for instance, was 87 years old when she 'retired.' Her final wish is to not be replaced until a new President had been sworn in, which was predictably not granted. She had 30 years to choose that presidency herself, but simply refused to do so.
This assumption was destroyed during the first Trump administration and continued being eroded in his second. They do not practice good opsec. (See Signal app usage) Nobody is enforcing policies, and nobody tells the bosses that they can’t do something because [reason].