Once the arrival of recorded sound came along, so did the arrival of recorded noise. Noise has been the bane of recording engineers since ... well ... forever.
While the first 100 or so years were spent trying to reduce or eliminate noise introduced by the recording medium (tape, movie film, phonograph disc, etc.) with the arrival of digital recording, we came to a point where we could focus on reducing or eliminating noise that was actually part of the recorded environment, rather then the recording medium.
While digital audio does represent a dramatic improvement in the ability to record sound via greater signal-to-noise ratios, lower distortion, increased dynamic range, frequency response and more, there are still noise issues in the digital world. Fortunately, these are minute compared to the days of analog.