A NAS need maintenance and can get expensive.
not because of the hardware.
LTO tape take a lot of care, I just read about it again.
It needs proper storage and maintenace
just like optical disks
Optical media last 50+ years and storage conditions is just normal home climate.
that's not what I read. fewer years, sensitive to dust, temperature changes through thermal expansion, sensitive to sunlight, to humidity because of molding. sensitivity to movements, because if you store them in those spinner boxes, they will scratch each other as they spin when you move the box around.