For backups, it’s generally best to make a backup, download it somewhere off the HA device, then delete the backup from the HA device. The backup almost does no good sitting on the device you’re trying to backup. If the device fails, your backups could as well and you might not even be able to access them again to restore it. AFAIK, the built in HA Backup system doesn’t provide a native way to do this, or a way to ignore the backups directory from getting backed up. I’ve seen a plugin that backs up to a google drive, which would be better if you use google drive. I haven’t used it, so can’t vouch for it, but you can check this out: Add-on: Home Assistant Google Drive Backup
Here’s another one that will backup to a samba share, allows scheduling, deletes old backups, etc: hassio-addons/samba-backup at master · thomasmauerer/hassio-addons · GitHub