At the moment I using sync obsidian by github and plugin
I see that obsidian offer sync: Obsidian Sync, it is worth?
At the moment I using obsidian only on desktop, not mobile, but I have git history, obsidian sync, offer also history repo like github?
Obsidian Sync only saves up to a year of version history, and does not include commit messages. Version history - Obsidian Help
I use Obsidian Sync, I like it, and I think it’s worth it. The Help pages about Sync should give you a sense of how it works. But if you’re happy with your current setup then there’s no reason to switch.