Commit squashing has the benefit of keeping your git history tidy and easier to digest than the alternative created by merge commits. While merge commits retain commits like “oops missed a spot” and “maybe fix that test? [round 2]”, squashing retains the changes but omits the individual commits from history. Many people prefer this workflow because, while those work-in-progress commits are helpful when working on a feature branch, they aren’t necessarily important to retain when looking at the history of your base branch.
— Squash your commits – GitHub
New feature allows for cleaner commits in your code and more suitable for a broader range of workflows.