I think automatic software updates are only a good idea if you absolutely trust the developer. You have no choice (generally) with browsers and OSes because you’ll subject yourself to security exploits if you don’t update.
For offline software like Obsidian, though, it’s not worth having auto-updates on. It worked fine as it was yesterday, and then an auto-update changed the text font. I don’t know what the old font was! Nothing looks right. I could have saved myself the trouble by looking for the auto-update setting and turning it off ahead of this.