To be fair to Obsidian, the default view is like three panes making it look busy, but you can toggle off both the left and right sidebar, leaving just the edit view which can be switched between edit and reading modes. Even the various toolbar icons need not be visible, and you could just use shortcuts to call them.
I use Syncthing to sync my Obsidian notes between desktop, server, Android, iPad, and Android tablet - it happens seamlessly in the background complete with version control.