Tape has it's own problems. LTO drives only have 2 generations of backwards compatibility[0] and nobody makes new drives for old formats. So if you have a whole library of tapes you'll need to copy tapes over periodically to newer formats just to retain access to them, which is expensive.

And once you start doing that, you've just quashed THE advantage tape had over disk. LTO doesn't provide any more reliability, it just shifts the failure points around. Instead of 20 year old sealed hard drives with bearings that will seize up and render your data unreadable, it'll be perfectly stable 20 year old tapes that no drive in the world can read. I'm also skeptical of the cost savings from cheap media once periodic remigrations are priced in, but it might still win out over disk for absolutely enormous libraries (e.g. entire Hollywood studio productions).

And no, there isn't some other tape format that has better long-term support. Oracle stopped upgrading T10000 around 2017, and IBM 3592 has an even worse backwards compatibility story than LTO.

[0] LTO-8 drives only have 1 generation of backwards compatibility because TMR heads get trashed by metal particulate tapes