The Critical Path Method helps project managers develop and manage the schedule in the past.
This method makes the life of a project manager easy. They can plan activities with less effort, and this was a good communication tool.
However, there were many issues with the schedules developed by critical path methods. These schedules were not realistic, and projects started getting delayed, which caused crossing their cost baselines.
Many times these delays led to project termination, and this was hurting companies financially.