There are other solutions via plugins too. E.g. Dropbox, Google Drive, or GitHub. There was a post earlier in HN which is a reimplementation of Obsidian Sync, but it seems their reversed engineering uncovered something not secure there and Obsidian soon made a patch breaking that. There might be workarounds to fix it, but I haven't closely follow it.
When I have the time to do the refactoring and cleaning, I will probably choose one of these alternatives (or even an alternative of Obsidian if there are better solutions for me.)