I'm confused - I and many others basically have these cobbled together LTO setups. I'm only "Prepping" by finally moving some of my backups away from home, so in case of a fire or whatever I'm not out of luck. You could cobble one together now for anything from OG DAT tape to LTO-10 for ~10K, if you need. So big fire happens, you file an insurance claim, and as part of the payout buy whatever setup you need, or hire some specialists. Once we are at LTO-20, there's no reason to assume LTO-10 and older drives are totally gone from the used market?

I'm not preparing for some asteroid impact level event, in that case the loss of my backups will presumably not really matter all that much.