For any really important data, you should always have at least 3 copies. 1) Your working copy on your computer. 2) A local backup which could be an external hard drive, a NAS, another computer, or whatever. 3) An off-site backup. That could be a cloud service, a computer at a friend’s or family member’s house, an external hard drive in a safety deposit box, etc. The off-site backup is in case your house burns down or is robbed.
If it’s REALLY important, you may have even more than that. There’s also the issue of how often do you update the backups. A hard drive in a safety deposit box is hard to update compared to uploading to Google Drive which can be automatic, but the hard drive in the safety deposit box is more secure. So you have to weigh your pros and cons.