Yep, also I wanted to mention that you do not need to do full file backups each time you do a backup. A good backup routine would be something like this.
Do a full database backup weekly.
Do a full file backup monthly.
Do backups of folders and files that change regularly/frequently on a weekly basis.
The rule of thumb is let’s say the worst case scenario does actually happen then how much data are you willing to lose if the sky does come crashing down? An hours worth of data, a days worth of data, a weeks worth of data or a months worth of data. WordPress Core files are easily replaced by reinstalling WordPress and are not considered data. Data is your post content, comments and other data that is stored in your database. So obviously the most critical and important backup is your Database backup.