I feel like other languages also have the issue of complexity and changing over time. I doubt I know all of C++ post C++14 for example (even though that is my day job). Keeping up with all the things they throw into the standard library of Python is also near impossible unless you write python every day.
Rust has an unusually short release cycle, but each release tends to have fewer things in it. So that is probably about the same when it comes to new features per year in Python or C++.
But sure, C moves slower (and is smaller to begin with). If that is what you want to compare against. But all the languages I work with on a daily basis (C++, Python and Rust) are sprawling.
I don't have enough experience to speak about other languages in depth, but as I understand it Haskell for example has a lot of extensions. And the typescript/node ecosystem seems to move crazy fast and require a ton of different moving pieces to get anything done (especially when it comes to the build system with bundlers, minifiers and what not).
Even C, we are now at C23, and I bet most folks only know "my compiler C", and not even all the extensions it offers.
Languages should be small, not large. I find that every language I've ever used that tries to throw everything and the kitchensink at you eventually deteriorates into a mess that spills over into the projects based on that language in terms of long term instability. You should be able to take a 10 year old codebase, compile it and run it. Backwards compatibility is an absolute non-negotiable for programming languages and if you disagree with that you are building toys, not production grade systems.