What's the Point of Local Backup?

I've been struggling with getting a good local backup of my Synology. I had just been having this one eight terabyte drive, but that thing fills up real quick. So then I thought, Oh, what's the point of backup if I'm not backing up everything? And so I took some other old eight terabyte drives that were just sitting around. Guess what? Easy peasy lemon squeezy with that little, uh, a dong. They each get a sticker on the drive. They get a stickers on the end that goes into the drive and they gets a sticker onthe end that went into the Synology. Do you ever have to enter in a good password on