Tape suffers from bit rot too. Radiation doesn’t target just HDDs and SSDs. Look, I don’t know what to tell you. I deal with a lot of large companies and I lived through tape’s hayday. The cost to archive data on disk is not high and companies don’t have issues doing it. Having it on disk prevents bit rot, because the pools are massive and are auto-healing. Also, the only way that your archive is not going to be long term is if humaity ends. Seriously, what do you think it would take to destroy a multi-AZ glacier archive?