There is not escape from hardware failures and software failures. About 15 percent of failures are related to hardware and the rest 85 percent are software related. And in case of failure of any kind, your website data is at risk.
True that your web hosting company has been giving you assurances that they are backing up your website daily but there are frequent instances when these companies act lazy and in case of a failure they do not have any backup data to restore on the new server. Your website is your livelihood, so you should backup your website yourself too. You simply can not leave it to others. Because if you do not have backup in case of a disaster, your whole business might be ruined. Therefore, it is important that you backup your website to safeguard against irrevocable data loss and a profits and revenue set back.
You should backup your website to keep a complete and updated data including blog posts, attachments, email subscribers and clients because otherwise you will simply loose your clients to your competitor if you do not take backup of your website and a disaster strikes.
It is also a daily event that WordPress websites get hacked and the hackers steal or destroy data. So in order to safeguard and reduce the recovery cost, it is important that you backup your website on regular basis so that in event of a hacking, you have your clean backup data to fall back upon and restore your website without suffering any major setback. Because recovery of hacked websites is very costly and may take many days. Whereas you can simply restore your clean backup within minutes.
Because of the above reasons, it is vital for your business continuity that you backup your website on a regular basis because with a current backup of your website, you will feel have a sound sleep without worrying about hackers and hardware or software failures affecting your business.