Markdown supports two syntaxes for bold/italic but Obsidian only natively supports one via the Cmd+B / Cmd+I hotkeys.
Obsidian only uses asterisk-based notation when using the hotkeys: *This is italic*, **This is bold**, ***This is bold italic***.
Markdown also supports underscore syntax: _This is italic_, __This is bold__, ___This is bold italic___.
For some users (myself included) the underscore variant is easier to read in edit mode because there is less clutter during reading and it makes the marked text more visually distinct.
Proposed solution
Add option in Settings > Editor to choose between asterisk and underscore syntax. Once selected, the bold/italic hotkeys honor this preference.
Current workaround (optional)
I have to manually use underscores since the hotkey doesn’t support this option.
I use underscores for my italics and asterisks for bolding and it would be great if there was a user option to select which syntax Obsidian is to enter when I activate cmd+I and cmd+b.
I didn’t see it mentioned here, but there’s a nifty plugin: wrap with shortcuts that lets you set custom wrappings. If no text is selected, it just inserts the tags with your cursor in the middle.
I’ve set a wrap for italics, removed the default hotkey, and set cmd/ctrl+i for this.