One of the ways in which such btc addresses are important is as a signal to others that these addresses are considered “special” by the owner and worth close attention, such as generating a “look-alikey” vanity address that is designed, in the right circumstances, to sneak under the user's perceptual filters.

Re-use of btc addresses (either “vanity” or “favoured”) leaks information and opens up the attack surface so is not consonant with a “total opacity” approach.

Just sayin'.

Cheers

Graham