If you have an offsite copy of your files (and not in a sync service like Dropbox) you are already in a better position than most.
Restoring from offsite takes time, even with Backblaze’s option of shipping a hard disk. You may also have data corruption troubles, companies may close all of sudden. It’s just not as convenient as local copies.
A further copy that is locally available is simply a better strategy. Adding more copies after these two is not a bad idea but you start getting hit by the law of diminishing returns.