Joplin’s WYSIWYG uses rich text, not markdown, and has a number of limitations acknowledged by its developer, including not working with their mobile app. I doubt Obsidian will ever have a rich text mode, as most Obsidian users chose it because we prefer markdown and plaintext to .rtf files or storage of notes in a database. If that’s what you want, you’d be better off looking for a rich text PKM app.
Obsidian’s live preview is true markdown and works exactly as it’s supposed to: the markdown is visible when you’re writing or editing it, but hidden otherwise. Most Obsidian users are happy with it (and were overjoyed when it was first released), and those who don’t like it generally use source mode instead.
You can open the same note side by side in source and reading modes in Obsidian, which is similar to Joplin’s dual view mode.