I use multiple backups, both usb and HD; the more redundancy the better. I doubt the inkjet prints will last very long. Perhaps a return to tintype is the solution.
We’ve migrated from a society of sentimentality and keepsakes to a society of disposal and short-term use. My children won’t see nearly as much of me as they will of my parents and those before them since most of my photos are on password-protected disk drives with high-level encryption.
It’s a hassle to continuously migrate your pictures to new devices, but continuously backing them up will ensure that they last forever.
There are also optical disks out there with a guaranteed 30-year life span, and some high-level backup systems use DVDs with protective cases that are guaranteed for 50 years. They’re available to the public, but be prepared to pay the price for archival. Disk drives are better IMO.
Re: lifetime of inkjet prints
I saw some beautiful (and expensive) prints of artist paintings and asked a gallery employee how they were made. He said with a large inkjet printer.
The lifetime of a print depends on the ink and paper, not the method of putting the ink onto the paper.