Recently 123-reg, a large hosting company, managed to wipe a lot of the servers and the websites hosted on them. Were you effected? If you were could you recover what you lost?
Cavespider has been around since the nineties and this isn't the first time I have seen this kind of thing happen. This is why I keep a weekly backup of all my managed websites on a local server, archive as well as a completely seperate cloud based service. This is three seperate places the back ups of my clients websites are kept.
I am often advised to use online automated backup facilities that many hosting companies provide. Had I used this with 123-reg I could well have found that I had not only lost the website but the back up too. Recovery would have been very difficult if not impossible.
There are of course many solutions to this especially if you have more demanding website requirements. We could arrange mirror servers that are clones of your website. They can be brought online for all sorts of reasons. You could have automated off site backups but these are only good if somebody occasionally checks that these are viable. Nothing worse than than needing your back up in a hurry and then finding it is unuseable.
So, it's worth being safe and keeping a backup of everything, knowing where it is and that it is safe.