That doesn't help if you have three drives to backup. You would need to repeat the process for each drive whereas TimeMachine will do all the drives automatically. Also a clone is only useful when you make it. You can't add to it. A month later if you weren't continually making them then you are are looking at losing a month of photos, email, documents, tax, etc. TimeMachine is set and (almost) forget.
Replacing all of the data for each clone takes a long time and is hard on the drives. Bringing a year old backup up to current status only involves the changes since it was made.
I don't understand this. With Carbon Copy Cloner, you can set it to automatically backup a series of drives. And, as far as I am aware, you can set it so that it only addresses any changes made since the last backup, so that it is not replacing all of the data each time it backs up.
I realize that Time Machine is a different kind of back up process than CCC, in that you can go back to earlier back up states, but that is different matter. Although, I think you could do something sort of similar with CCC, on a limited basis, if you set it to back up one drive to different drives or partitions, on different schedules, although that would seem ridiculously cumbersome to do, and it wouldn't save earlier backups indefinitely, as is possible with TM.
