So it is about toolchain or counting users?

Change of speech when it doesn't fit?

It's about both, the toolchain and language is used by users, so there's no need for a toolchain (or indeed, any piece of software) that has no users. Or rather, I should amend my earlier point to be, of the languages that are generally used by people, ie are not niche, Rust has the best toolchain of them. I consider most MLs these days to be niche, for lack of multiple high profile projects in those languages.

So Rust also has a debugging experience at the same level as Rider and Visual Studio.

The ability to hot load code dynamically, fast compile-debug cycle thanks to a JIT and REPL, in addition to a native code compiler.

Being able to plug into OS events like ETW, Instruments and perf.

Cloud infrastructure tooling for container orchestration.

Being able to be hosted inside SQL Server for writing stored procedures.