Mute all sounds except for a particular app

This was a great question from user/author robmozd, asked back in 2020 and it got little attention. This would be such a great feature for Apple to add. And if that isn't likely, does any one know a way to do it...or an app that already does this only. Would love it if people weighed in. Thanks.

Here is his query again, exactly as he asked it.

"Can you mute all sounds except for one app easily?

I would like to easily listen to sound from a particular app while at the same time not being disturbed by other sounds. Is their a way to do this easily via a single toggle or action.

i.e. toggle on > only this app could be heard

toggle off > back to normal and notifications etc could all be heard

Thanks"