And this is the problem with YouTube shorts—they've been designed exclusively for the mobile experience without any consideration for desktop.

On desktop it's always been customary to allow adjusting the volume on each piece of media individually, because multitasking is not uncommon. Some people will want to be able to adjust the volume of YouTube independently from the volume of the video game they're playing at the same time. Or even just turn the volume down while still having full volume alerts from Slack.