Drum scanners gave way to other technology because people quit caring about quality. Convenience and novelty became what people like.
There has never been anything better or more appropriate than good quality glass lenses, incandescent lamps and photomultiplier tubes to make the most beautiful and analog of scans.
Dr.-Ing. Rudolf Hell made some of the nicest drum scanners from 1963 with the introduction of the Chromagraph scanners.
Here is the DC 300 series, circa 1970s.
Here is the DC 3000 series, circa late 1980s. The DC 3000 series models from the 1980s and 1990s are still today some of the best drum scanners in use. In the late 1990s, then under the Linotype-Hell and later Heidelberg companies, they went to the vertical drum with the Tango and Primescan models. These are also very nice and stll in use today.