When reading A Quick Guide to Bitwarden Client Applications, I see for desktop applications the following:
Desktop applications provide a native experience for Windows, MacOS, and Linux, and can be useful for areas where web browsing is not part of the typical workflow.
What would that be? The ability to automatically fill-in entries for other native applications (such as, say, Spotify)?
They are also ideal for storing and referencing other types of sensitive information besides passwords, such as credit card and bank account numbers.
How is that different from having them in the vault available from the web browser, or in the extension? One would in the vast majority of cases use these information on a web page anyway (so it would either be available directly from the browser extension, or the vault - in which case it is equivalent to go to the desktop app)