Enable the required system extension. Reduced Security?

I want to back up my Mac to my Synology NAS, so this is not the correct place to post this question. I have been looking to replace Time Machine with something else, because I have a Synology. I was thinking of using Synology's Active Backup for Business, or because I have a subscription to PCloud drive. The issue with both PCloud Drive and Synology's ABB is that I need to " Enable the system extension required for mounting volumes." " To do this, shut down your system. Then press and hold the Touch ID or power button to launch Startup Security Utility. In Startup Security Utility, enable kernel extensions from the Security Policy button." With that said, I'm unsure if I can disable kernel access once I've done this, and I'm also uncertain about the safety of these programs and what else might be lurking if I enable them. Are things like this generally safe? Why do I need to do this in the 1st place?