I use fossify contacts, which allows you to read and write your contacts to/from a VCF file (as opposed to import/export which must be manually done, this keeps them in the file so as you add/remove contacts the file is updated) and synching to keep the VCF file synced between my devices. No servers of any of that maintenance overhead needed.

You can use synching for all kinds of stuff too. I sync calendar (with fossify calendar) and a keepass PW database and 2fa keys this way.