Cross system / OS landscapes can make it nearly impossible without Obsidian Sync. It's okay for Android & Windows, but if you throw an iPad into the mix, you can't really find a local/cloud sync for them all. iOS especially has some limitations on how apps can access files, so your only options are iCloud or Obsidian Sync.

For more info see here: https://help.obsidian.md/Getting+started/Sync+your+notes+acr...

This is untrue, I use iOS Working Copy connected to my git repo which contains my Obsidian vault. It's also on on my android pixel phone and I have it on my windows machine. Everything syncs just fine using a private github repo.

Do you use end to end encryption? I don't want 3rd party companies to see my data.

Of course obsidian is not open source so I can't guarantee their e2e sync service doesn't sneakily send the data to their servers, but it's still less risky than having it easily available to the company employees.

I use a community plugin that saves to a Hetzner storage box, which support webdav off the shelf. Works flawlessly across all the platforms you mention and Linux too.

I use the sync feature, but its not required. There are several tutorials for using got with a community plugin or an alternative like syncthing.

Its just text after all. Which is the point of using Obsidian.

Paying for sync is like paying to support the software development. Which is worth doing for Obsidian. Plus I find it useful. I am on the older lower rate.

Obsidian saves to a bunch of openly accessible markdown files. You can sync them however you want.

I use Syncthing to sync between my android phone and my computer without a subscription, and everything has been working perfectly.

On iOS/macOS you can use iCloud Drive to synchronize without the subscription. It doesn’t work flawlessly but it’s „ok“.

There's a plugin called "Remotely Save". I use it to sync to nextcloud (webdav), but there's also another plugin for syncing to a git repo.

And worst case, you can use any 3rd party file syncing tool like nextcloud, dropbox, syncthing, etc since it's just a directory of files.

I have it synced in a git repo, and I use their apps on windows and macos. I lazily use the git plugin to commit and push changes, but you can do at all in the command line if you wanted. Reminder, it's a bunch of plain text markdown files so commit away.

I used the git plugin for this on my iPad. This uses a JS based git version.