It allows me to make several changes, then leap back and forth to see their effect en masse. I can't do that as easily if I have to undo one step at a time. I can undo and repeat a crop, for example. It may be that layers provide an alternative route. I can also see a list of the things I've done, perhaps so long ago that I've forgotten them.
I know its not the same as a history, but its easy to clone a variant in C1 (single keystroke), change an aspect of the edit, clone again, make further changes, clone again make further changes etc Compare all clones in a multi-view, delete the clones you don't like and continue editing on the remaining clone.
You could, as you suggest use layers, and switch between them, but the cloning approach is actually really fast, and allows comparing multiple images at once rather than switching off and on layers, or indeed switching back and forth between places in the history.
I also often end up with saving clones as snapshots of key editing stages so its easy to back track if I need to.
For very subtle editing where you might want to back track through multiple brush stokes, this is obviously not much use, but for what I think of as everyday editing, it seems to work well.
Cheers,
Graham