And further - the establishment of a single, fediverse-wide account for each user would make it far too easy for those so inclined to silence anyone they wanted merely by banning their one and only account.

It’s not a matter of how ones profile would be accessed, but how it would be created in the first place snd how it would be managed.

Necessarily, those who implement the creation of accounts have control over how they’re created, who is allowed to create them and how they will be handled after creation.

Any scheme to establish one “central” (your own term) account for the entire fediverse will necessarily be managed by one “central” service, which means one “central” authority over account creation and management

Decentralization is a feature - not a bug.

Setting aside the veritable TITAN-loads of shady shit Palsntir is up to, it’s also worth noting that Reddit’s policy changes have made it clear that providing a platform for the spread of disinformation is a central part of its current business model, so I’d assume that not only is Palantir using it for that purpose, but that they are far from alone.