Very easy with CardDAV. Sign up for a Nextcloud account, install DavX5 on your phone, and setup CardDAV sync on your PC in Thunderbird/Gnome/etc. You can also use Etesync if you want more security, although it definitely is more challenging to use.
Anyone have any follow up reading? I would love to read more comprehensively about how many of the mentioned ideas would actually be implemented in a cohesive system.
All the answers I’ve seen so far don’t seem to account for metadata. You might want to have a look at tox over tor, xmpp over tor with omemo, or session if you are concerned about it.
Very easy with CardDAV. Sign up for a Nextcloud account, install DavX5 on your phone, and setup CardDAV sync on your PC in Thunderbird/Gnome/etc. You can also use Etesync if you want more security, although it definitely is more challenging to use.