i have >100GB blu ray media, and that's
writeable. So those exist. My BD-R from 2016 reads them correctly and can write them, so it's not some "recent" thing, except maybe the capability to create the media. I think the largest BD-R available are around 120GB.
Luckily, the gen 7 tapes are 10-100 times that large, depending on who you ask. Each disk costs approximately $2-$5 as well, assuming you get some sort of discount. Tapes are more, they hold more, but at a certain point having a disc in a jewel case is better than having some tape. bluray drives are easy to find, tape readers, not so much.
