I prefer keeping unfinished features out of my deployed code base, so I keep them in branches.
Lets say person A and person B are working on two features both committing to master.
Person A commits some work to master and pushes to origin. Person B commits some work and pushes to origin. Repeat this a few times, now you want to scrap the feature person A is working on. How do you cleanly handle this?
That said, it seems you are suggesting that the workflow should be centered around rolling back features rather than commits? That being the case, if your feature spans multiple commits, then indeed you have something there. If your feature does not, branching probably isn't needed.
Sure, if you work in some sort of enterprise or corporate environment.