BASIC was meant as a teaching language. Python is a real language that’s simple enough to be a teaching language. It also runs the same dialect on every machine, which BASIC never did.
Being the second best language at everything, it gets used for everything because people don’t want to learn the first best in any given niche. Python isn’t the best choice for numeric applications, but with NumPy, it’s adequate, so why bother learning R? Even if you knew R already, you’re going to run into a lot of Python code for that domain from other people. You’ll be swimming against the current, and why bother?