I use git to sync Obsidian. Termux on Android and git on any other device. I have two scripts, one .sh one .psh, that I run to just commit and push the latest changes. On Windows I use the plugin shell commands for one-click running the script, on Android I need to use termux.

It’s not the easiest but it is, at least to me, easy to set up :)

It’s 2 and 3 for me.