Paradigm shift is a term that can be misapplied.
Some use it to describe new methodologies; that is, new ways of doing things.
In fact, the term is closely associated with Thomas Kuhn’s 1970 classic The Structure Of Scientific Revolutions. In his book, Professor Kuhn examined some of the major scientific upheavals of centuries gone by: the change from Ptolemaic to Copernican astronomy, the shift from the phlogiston theory of combustion to the discovery of the element oxygen, and the revolution that caused Newtonian physics to be replaced by Einstein’s theories of relativity.
In each of these instances, although the practical ramifications of the scientific change may have been minimal, the change to the theoretical underpinnings was enormous. For example, the practical application of astronomy in Ptolemy’s time was to help farmers predict seasons, rainfall and that sort of thing through observation of celestial objects. That didn’t change a great deal once the Copernican system was adopted, except that by employing the new tables, the predictions were more accurate. However, the theoretical predicates behind the later theories were entirely different. The same was true about the shifts following the change in understandings regarding the the role of oxygen in combustion and Einsteinan physics.