It’s not that the 15 minutes isn’t tolerable. It’s that it’s going to be scheduled poorly for someone, perhaps the entire team, in such a way as to break focus and drop context.
A previous team I was on had standups at 10 am. This meant even if you wanted to start working earlier and get heads down on something, there wasn’t much point. Add in the typical context loading time and that meant you weren’t really able to get going until 10:30. And guess what? At that point, lunch is an hour and a half away.