It is highly imperative that, your entire website gets a regular full backup, including databases, everyday.
There can be testing times, like you make a small change and your site crashes. Or there could be malware attacks or DDoS attacks on your web server. Your website can get hacked by a hacker.
In such uncertain times, if your web host did take a full backup, then using that backup, your web host can recover or restore your website in no time. And you will get your website the way it was, prior to the crash.
Some web hosts permit you, the site owner, to take backups (and restore if needed) when you like. This is in addition to regular scheduled backups. This can be handy and this way you don't have to depend on the web host to restore your site for you.
So basically, Make sure your web host take regular backups - daily, weekly and monthly.
In addition to a good backup plan, good web hosts provide top security features so that hackers will find it difficult to hack your site. New security measures like Two-Factor Authentication for your control panel login, makes your website more secure.
In addition, good web hosts perform regular scans of website files to find if any file is infected with malware and then alerts user to take necessary action. Also, an advanced software like CloudFlare, can significantly decrease spam and other attacks and at same time improve site performance.