This is why you low-pass audio before quantizing. If you put the square-wave through a low-pass filter before recording it digital and on high-quality tape, the digital recording will be more accurate than the tape.
This was a digital recording onto a professional digital system. It was put through a Nyquist filter.
Then again, is "accurate" in some mathematical sense the right term? Which one sounds more like music? Among audio professionals, there's a broad consensus that tape sounds better - enough so that there is a strong market for digital plug-ins that emulate the (mis)behavior of tape.
If a pure-digital master can emulate tape, then isn't it superior to tape?
(I know that many analog systems have soft-rolloff allowing you more leeway in setting your headroom, but modern ADCs have so much dynamic range that it's a poor operator who doesn't allocate themselves sufficient headroom).
