Redbook: only 1/4 of the master tape???

The 1/4 of master tape stuff is nonsense. I do agree with you that information is lost at every transfer stage. It just isn't a 4 to 1 reduction. You're also misusing the term compression.

It's not just an issue of sample rate, you also have to consider word length. Redbook CD uses a 16 bit word whereas better quality digital recording and processing is done at 24 bit or higher. The sample rate conversion process usually entails the altering of both factors. Opinions differ but it's my experience that word length reduction is more noticeable than just a reduction in sample rate. There are different algorithms for accomplishing SRC and some are clearly more transparent than others. The amount and type of dithering also has a major influence. It's misleading to ask what is the ratio of loss in that the data reduction does not linearly correspond to what the ear hears. Depending on the type of music, the skill of the engineer and the choice of SRC processing the conversion from 96/24 to 44/16 can be very noticeable to barely perceptible. Roughly speaking it's of the magnitude of going from analog tape to vinyl.

You certainly don't need an infinite sampling rate to capture live music let alone what's contained on a first generation tape. In theory a 192kHz/32 bit recording should have 192dB dynamic range and be completely linear out 48kHz.