Files can easily get lost if you don't have good protection on your website. Some of those files may be saved in your computer and easily replaceable, but what about the rest of them? If you lose the first time to them, where are you going to get them out of again? Especially how to fix hacked wordpress is vital. Long-term sites have a good deal of data and have made a number of documents. Recreating all that would be a nightmare, and not something click to read any business owner wants to do.
Also, don't make the mistake of believing that your hosting company will have your back so far as WordPress backups go. Not always. It has been my experience that the hosting company may or may not be doing proper backups, while they say they do. Take that kind of chance?
Move your wp-config.php file up one directory from the WordPress root. WordPress will search for it there if it can't be found in the main directory. Additionally, nobody else will be able to read the document unless they've FTP or SSH access.
Along with adding a secret key to your wp-config.php file, also consider changing your user password into something that is strong and unique. WordPress will tell you the strength of your password, but include numbers, use letters, and a great tip is to avoid phrases. It's also a good idea to change your password regularly - say once every six months.
I prefer using a WordPress plugin to get the work done. Make sure is able to do copies, has restore functionality, and can replicate. Be sure it is frequently updated to keep pace. There is not any use in not functioning, and backing your data up to a plugin that is out of date.