Is this question really being asked? Always backup the data ;-) Even redundant configurations should back up the data.
Why? Because not having a backup means not being able to recover from "your" #@)(*$)@#$)(#$*) moment. I used quotes as I didn't want to accuse any particular person of having one of those moments.
Time machine makes the process quite easy. Between that and the low cost of drives, it's only a fool and his data that are soon parted.
Are there better backup solutions out there? Undoubtedly -- but it works well for its intended task.