…if competently encoded.

You can absolutely hear the difference between a bad MP3 and the original. I used to amuse myself and friends by quite reliably identifying the difference, blinded, using a rather bad pair of speakers.

Actual CD audio can also work quite differently than any encoding, as at least older CD drives had an entirely separate analog output cable that connected to the sound card and bypassed the ATAPI link entirely. Levels wouldn’t even be matched.

To be fair, that's true today, but not in 2008 when this article was written. MP3 encoders have come a long way and bitrates are typically much higher.

I can definitely hear the difference on some songs at some “CD quality” bit rates of MP3. Also some MP3 encoders (and decoders too, to be fair) are better than others. Particularly back when this article was written.

That all said, these days encoders are much better, and there’s no excuse not to go for 320kbps (assuming you have to use MP3).

What I find more interesting is that there was a period where some people who grew up listening to MP3s preferred the artefacting they introduced vs lossless. In much the same way how vinyl enthusiasts like the colouring of the sound that medium introduces. Which just goes to show that as much of this is down to psychology as it is technology.