Note that it is always a good idea to periodically back up to a separate USB hard drive, connected only for that purpose, and disconnected (and unplugged) thereafter.
How long does a USB last? I have a USB loaded with some pictures that’s been sitting on the shelf next to my speaker for a couple of years.
If your data is valuable then buy two USB hard drives and alternate them. Apply label stickers to them dating the backups. Store the newest copy in a friend's or relative's fireproof safe or a safe deposit box and swap them out on a schedule or when convenient. I used to store the latest copy in my BIL's gun safe. My SIL would come visit my FIL weekly and act as a courier. Simple, secure, inexpensive.