The even bigger advantage of python is everything else: web scraping, interfacing with weird APIs, hitting the database, consuming and emitting obscure formats, parsing text, calling operating system services, and a million other things. That and much much better abstractions for building larger systems out of reusable components and much better tooling for serious software engineering.
R or Matlab can be fine at exploratory data analysis, making charts, running miscellaneous bits of non-programmer-grad-student code found on the internet, etc., but as soon as you want to do anything other than data analysis, they quickly become annoying.