I was considering trying to use Python on Codeforces, so I wanted to find a top rated contestant who uses Python as their main language. Turns out no red contestant uses Python as their main language. I compiled this list of who uses which language.
Not surprisingly, C++ dominates — about 95% reds use it:
C++: 262 Java: 12 Python: 3 C#: 1
Note that all three Python users were actually just messing around with the language recently, but they use C++ as their primary language. See the gist to see who uses which language + which compiler/version.
I think this is a shame, because there are many wonderful languages that simply don't get used because people fear they are slower than C++. Many problems are designed in a way that requires careful optimization even in C++ and are simply not solvable in other languages.fr
I think having execution time multiplied by a constant that differs per-language would be are a reasonable solution to penalize C++ and Java. Hackerrank already does this. If Codeforces, the most popular platform, started doing this, it could help getting the competitive programming community out of the C++ feedback loop: everybody supports C++ because everybody uses C++ because everybody supports C++.
Another way of solving the problem is to use the open-data format, which is obviously not an option for Codeforces, but Google Code Jam statistics illustrate that there is a demand for other languages as well.
Getting out of the C++ loop would help getting more people in the community because they wouldn't be forced to learn C++ (not the easiest of languages) just to stand a chance. If more people started using different languages, they would have more support, resources, tutorials etc. -- think of how every tutorial on an algorithm, technique or trick is currently written in C++. For sure having implementations of crucial algorithms in something like Python would help a lot as well, if only because of how approachable it is compared to C++.