Matplotlib is far more capable than most users think.
Although I agree in general, as most people don't spent time learning matplotlib properly, the real reason why we move away from matplotlib towards other libraries is because matplotlib is not very pythonic and it is not obvious how to achieve things as there are at least three completely different ways creating plots and figures. That feels cluttered, ugly and error prone and you always have to look up all the nitty details. Seaborn, on the contrary, is much simpler, more straightforward and just easy to use, and it works very well with pandas DataFrames, which is the second most important thing. We want libraries that fit well the ecosystem. But matplotlib is and always will be very important as it is the foundation. But I appreciate that we have higher level libraries that do the main work and only then we can do ela deep dive into matplotlib to change whatever needs to be changed but only if we need it and not from the beginning just to get something good looking and complete.
Interesting read, good to know matplotlib is more versatile than meets the eye, please do share a couple of lines of your MatPlotLib recipe, that would be really helpful!