Optical discs are now up to 300 GB and they have caddies the size of an LTO tape that hold 12 discs. Seek time is obviously better than tape but I don't know about the price. The only remaining vendors are/were Sony and Panasonic.
From a cheaper end-user/consumer point of view, the only real option for optical disc storage is BD-XL, which is a 3 or 4 layer Writable BluRay Disc supporting 100GB/128GB per disc.
In comparison to tape, it's not that much storage, but fairly cheap to implement at home. £60 for the drives, and about £15 per 100GB disc.
https://panasonic.net/cns/archiver/
https://perspectives.mvdirona.com/2016/03/everspan-optical-c... (Sony Everspan dropped off the Internet; did they go out of business?)