Admit it, before you could grapple with Tensorflow and Keras, the Data Science world had moved on to Pytorch. I am not even going to the time when “R vs Python” was still a debate. That almost seems a lifetime ago.
The mere introduction of a new library creates a demand for people “skilled” in it that completely changes the dynamics of the hiring wave. Doesn’t matter what else you could be good at, if you haven’t got that one shiny (no R-pun intended) new thing that’s burning up the market, your resume often gets passed up by potential employers. Staying in tune with the times is just not enough; you have to fight to keep yourself ahead of the times.