I think he means that you'd need 50 tape drives with the backup running simultaneously across all of them to run the backup in a day - fortunately that's not ho

I think he means that you'd need 50 tape drives with the backup running simultaneously across all of them to run the backup in a day - fortunately that's not how backups get run, you generally aren't running full backups every time, you run a full then do incremental or differential backups starting from that point with periodic full backups. The point I caught from the article that most people are bypassing is that tape provides a fully disconnected and unreachable (by attackers) backup, where many online backup systems are using software and systems that may be reachable from the systems being backed up. In the worst case of a motivated knowledgeable skilled attacker that could mean an attacker having the ability to wipe backups as well as live systems.