I really can't believe I am still having to ask this question. The last 12 page thread on this full of people begging for a fix was marked as 'solved' (which it wasn't) and then locked for being old.
Why is it I cannot cast audio from the Mac desktop app to my Google Chromecast device? At the moment it is only possible to cast from the mobile app. The previous workaround of using the web browser app whilst using chrome is not a solution. Please can you advise the community as to why you either cannot implement this feature or have chosen not to?