The best way to ensure your data lasts a long time is to use a laser to beam it to the darkest part of the sky. Read speed is abysmal though

There is a plugin for obsidian to work with syncthing, but it seems to still be in development, implementing through the app and selecting the folders also gave me a reason for syncing my camera as well, and was super easy, no portfowarding or anything required

Syncthing is the way, I had tried setting on nextcloud but never could get it to store how I wanted, but syncthinf was ridiculously easy and should work for anything that uses a folder