The issue is that not everyone is comfortable bringing up issues as they happen. Some people may not recognize issues. Others may avoid mention until a problem grows larger. Regular 1-1s make this much easier to catch and give direct reports a great opportunity to share.

Some people will say that this isn't required with a good company culture, but when people are involved nothing is perfect. Maintaining positive culture requires work. Recurring 1-1s are the bread and butter of management and in my experience the work pays off by staying ahead of things and preventing minor issues from turning into major issues.