This is a simple guide on how to synchronise contacts and calendars between a desktop operating system (Windows, macOS, Linux) and Android relying on a combination of Syncthing and Radicale. The main goal and idea is to have Radicale running on every system locally, so that you can connect with it even when there is no network connection available. This applies to both desktop operating systems and Android as well. Desktop: Install and run Radicale following instructions from https://radical...
This does not need a server.
Syncthing is a server. You’re replacing the server part of Radicale with another server software, which comes with extra overhead and complexity.
Wrong, Syncthing is peer-to-peer.
How many devices are we talking about?