Roam might use markdown syntax in some ways, but it is not a markdown editor. Markdown editors edit plain text markdown-formatted files. Roam is a rich text outliner with a proprietary data structure.
This is not just semantics. The difference allows both apps to do different things.
Sure, but your primary complaint is therefore with Markdown conventions and standards, not with Obsidian.
You should submit a feature request for this. Though, because you are asking for Obsidian to adopt non-standard markdown, I’m not sure it’ll gain much traction. All you can do is try, though!