One possibility, the original is in poor condition, such that an audio player resorts to error concealment.
But with a GOOD ripping drive, and software like EAC (secure modes) or CDEX (paranoia modes), it's possible that "iffy but ultimately readable" areas of the original have been recovered.
The MOST you can get out of a CD, is perfect digital reading, leading to audio performance as expected.
Any deviation from that will result progressively in:
1. Correction at C1 or C2 symbol levels (should be no loss of quality)
2. Concealment by interpolation
3. Concealment by muting
4. Audible errors - clicks, skips, stops, snatching
5. Loss of play, no play, loss of control
Unless an original is damaged/defective, you would expect a CD-R copy to perfom equally at best, and usually worse.