I take daily btrfs snapshots, and use btrfs send/receive to sync them to an external drive. It’s really fast, even for huge files like virtual disks of VMs. It does require root, though.
I grew tired of filtering out cache files and such, and just backup everything, including the OS.
Indeed there is! Just join a channel like #fsf:libera.chat from your Matrix client.
This bridge is not officially released yet, but it is very usable already.
See: https://matrix.org/blog/posts#liberachat-irc-bridge-work-continues
I share the link to Orgzly (available in F-Droid), which I set to auto-sync to a local folder. Then, I sync this folder, containing the org-mode files, to all my devices and Desktop with Syncthing. Nice thing is, the page title is shared along the URL, and you can categorize them within Orgzly as well. Downside is, you can do only one link per share, otherwise you get all the URLs but without the page title.
Just add a new adress book and choose “import an existing collection”. If you give it permissions, you can then select the Google account already on your device, and import it directly.