And a number of the library vendors' libraries last for decades with only drive/tape swaps along the way. The SL8500 is on its second decade of sales for exampl

And a number of the library vendors' libraries last for decades with only drive/tape swaps along the way. The SL8500 is on its second decade of sales for example. Usually what kills them is the vendor deciding not to release firmware updates to support the newer drives. The stock half inch cartridge form factor dates from 1984 with DLT & 3480. Given there have been libraries with grippers capable of moving a wide assortment of DLT/LTO/TXX/etc cartridges at the same time. Its doubtful if that will change anytime in the future. So if you buy one of the big libraries today it will likely last another decade or two, maybe three. There aren't many pieces of IT technology you can utilize that long.