If you operate an internet-based company, you cannot afford to be offline even for a day, let alone lose all of your data. Having a backup might save your life for a variety of reasons, not only in the event of a hacker attack. For example, I was directly impacted by an infamous accident in March 2021, when the OVH Datacenter in France was destroyed by fire. Fortunately, I had a complete backup of this website, so I was able to restore all of the content in a matter of hours.
To put it another way, a backup is a copy of your website that can be quickly restored to service if anything goes wrong with your server. Whatever happens, keeping regular backups of your WordPress site may save you a lot of time and trouble.
If you are still reluctant to pay for an automated backup, consider how much time and money it would take to reconstruct everything from start if a hacker deleted files or database entries. Restoring a website from an automatic backup usually takes only a few minutes. You will still need to address the security flaws that the attacker used to breach your site, but at the very least, your site will be usable again.