Tape is a lossy medium, subject to all kinds of problems like fading, increased noise, print-through, and so forth.
Early ADCs definitely had their issues, especially compared to today's, but in my limited experience much of the problem arose from mixing and mastering engineers unfamiliar with the medium. For example, it was commonplace to run the levels "hot" on tape to capture as much of the dynamic range as possible, and some soft saturation of the tape was acceptable and relatively benign. Clip an ADC, however, and the effect is immediately noticeable, and there were issues with ADC front ends having poor (and extended) overload recovery. Dither, though known, was not always included, anti-alias filters were sometimes not (nearly) as sharp as they needed to be (usually analog with ringing and phase issues since oversampling was hard to achieve in the early days), ping-ponging (multiplexing) ADC channels led to channel-channel time artifacts, etc. I think most of that was recognized and dealt with fairly early on, and became part of the learning process for design and sound engineers.
All that aside, some of those early CDs were still great, before the loudness wars alienated a generation on the technology.
IME/IMO - Don