I'm just talking about single drive units you manually swap tapes on. That would still make an excellent long term cold backup for me even if I did have to swap

I'm just talking about single drive units you manually swap tapes on. That would still make an excellent long term cold backup for me even if I did have to swap the tape s once a week but they're still 4k+ unless I go all the way down to LTO-5 tapes that are just ~1.5TB which could be good enough for critical things but not really helpful for backing up everything.