Can we talk about strict start times versus flexible hours on build sites?

I've been on sites where the foreman insists on a 7 AM sharp start, no exceptions... It keeps everyone in sync and jobs on track. But I've also worked with crews that roll in when they can, as long as the day's work gets done. Some say the flexibility reduces stress and actually boosts morale, especially for those with long commutes or family duties. Others argue it leads to chaos, with people showing up at different times and missing key morning briefings. From my own experience managing a team, I lean towards structure, but I see the appeal of flexibility. What's the consensus here? How do you handle start times on your builds?