It's an illusion, most people don't have a good sense of time. Just getting everyone in a room and waiting for the last person to arrive and everyone to leave, grab a cofee and start working again is at least 12 to 15 minutes for that amount of people.

Next time you have a standup, look at the clock once you get up to the standup, or that you stop working normally and start looking around to see when people are leaving to the meeting. And then look at the clock when you are back at your seat working again.

People start getting ready to the standup 5 to 10 minutes before, chatting while waiting, etc. Count the time that you have stopped working normally, where you can't do any large task because you know there is a meeting in 10 minutes.

Don't just count the time literally from the moment a person starts giving their status to when the last person finishes, as the real overhead of the meeting is not that.

I guarantee you if you do that systematically and count the complete overhead and not just the literal overhead, that at best it will be typically 15 minutes and for longer sessions half an hour.