An IBM 3592 JD Advanced Data Tape Cartridge costs a bit over $200 and has a raw (uncompressed) storage capacity of 15TB. An LTO-8 cartridge is 12TB and under $200. Meanwhile the cheapest 10TB HDD Newegg sells is $304.27.
Harddrives usually last about 10 years without power at best before you loose significant amounts of data (you loose bits beforehand, don't worry).
If you can find a working drive, and drivers, for a 30 year old tape. Look at all the problems NASA has with their old tapes. The tapes actually are fine, it's just a major effort to custom build a machine to read them.
You can still obtain LTO-1 compatible drives nearly 2 decades after the standard was released.