For archival media, being slow isn't a huge problem. You archive it, and, eventually, read back a little of it. When the time comes to migrate to a new format, you read it once more. Being slow also means it takes a while to overwrite it fully. And, if LTO-10 is not big enough, you can go with IBM 3592. If your tapes never leave the tape archive, who cares what is the shape of the cartridge you are using?

I also have a disturbing impression Microsoft has sprinkled magic AI dust on project Glass so that they could check that box. One can only hope it doesn't hallucinate your backups.