Tape storage? https://www.ibm.com/storage/tape
The market for tape is much smaller than consumer markets (in units sold)
You'll probably be able to read CDs in fifty years, just because there are so many of them.
If you have a fifty year old tape, even in perfect condition, you probably won't be able find hardware to read it.
If you have a fifty year old tape, even in perfect condition, you probably won't be able find hardware to read it.
As I found out when migrating a pre-LTO AS/400 tape, there are rental places known to IBM partners that rent the drives that can hook to modern equipment.