I think that most people would find it hard to schedule two months of continuous vacation, since their spouses/partners would not be able to take vacations on the same schedule. Also, many people care for children or elders, and their schedules are constrained by these responsibilities.

As someone's employer, you shouldn't presume to know what vacation schedule is best for their mental health or productivity. Some people may be happier if they can take shorter breaks more often. If you want to give your employees two months of vacation time, that's fine, but let them decide how and when to make use of those days rather than imposing your own preferences on them.