It's interesting that, with Python, the reference implementation is the implementation

yeah there's Jython but really, Python means both the language and a particular interpreter.

Many compiled languages aren't this way at all

C compilers come from Intel, Microsoft, GNU, LLVM, among others. And even some scripting languages have this diversity

there are multiple JavaScript implementations, for example, and JS is...weird, yes, but afaik can be faster than Python in many cases.

I don't know what my point is exactly, but Python a) is sloooow, and b) doesn't really have competition of interpreters. Which is interesting, at least, to me.