As a recording engineer for Chesky Records, I first started working with CD-Rs in the Summer of 1990, using Yamaha's very first CD-R recorder. It cost a cool $65,000 USD, and blank 63 minute discs were running upwards of $60 USD each.
At that time as now, the finished, recorded pit structure of a CD-R offers superior transitions from land to pit (bump) than on most any pressed CDs (JVC XRCD excluded).
Simply put, this produces an optical eye pattern to the laser reading mechanism of a CD player which creates much more accurate square wave patterns that are the analog representation of the digital signal.
It is here where jitter normally sneaks in, because the optical eye pattern must be interpreted by an optical sensor, whose accuracy is directly effected by the clarity of the eye pattern.
Small deviations in timing (jitter) are not recorded nor correted in our single ended 16-bit PCM recording system, and this has been a problem all the way back to 1980, when Phillips and Sony took a few short cuts.
The result is that the same data from a pressed CD will always sound more transparent when dubbed to a CD-R. It is simply a matter a physics, and lack of recording the time signal from the original A/D!