Searched for, but could not find a video of a robbery where the guard? owner? was carrying unchambered. Robber was focused on another employee when the guy drew his pistol and tried to chamber a round. Failed to chamber...twice...if I remember correctly. Guy was shot. The video was a good illustration of the speed at which this went down.
I carry because I want to increase my odds of survival IF something were to happen. I train to further increase the odds in my favor. I carry with a round chambered, DAO and no safety for the same reason. It did take some time to reach a level of comfort and confidence in doing this.
It’s very important for you to be comfortable with your choices. If a carrying with chambered round makes you uncomfortable, then train, train, train to become proficient in drawing and chambering a round. And be very careful. I would recommend using some type of dummy rounds like those made by AZoom.
Edit: Yep, that's the video in the post above.
A lack of planning on your part does not necessarily constitute an emergency on my part.