Back in the day of videotapes, each generation of duplication created worse signal until you ended up with nothing but static.
Nowadays, digital encoding allows perfect duplication of content, and any errors are caught and fixed using mathematical tests called checksums which add up the ones and zeroes, then compares the copies to ensure they’re identical.
The same applies for the doppelgangers of important people we copy for various purposes. Quantum checksum comparisons ensure we’ll get the right information out of a clone we’re torturing.
Oh, did we kill the clone?
Copy another, and try the knotted whip this time.