As early CD players were intended for audio playback, your CD player can lie to the software. It doesn't tell if it's reading at the exact beginning of a sector

As early CD players were intended for audio playback, your CD player can lie to the software. It doesn't tell if it's reading at the exact beginning of a sector (because timing information is multiplexed into the audio stream, and some CD players were not byte-exact when interpreting this), and it also doesn't tell you when it silently corrects some errors. Because for a human listening to the audio won't notice. But of course it makes a difference if you want to make high-fidelity copy. That's why there always have been copy apps (cdparanoia on Linux, EAC on Windows) that do overlapping reads, and then detect and compensate these problems.