People have been predicting the imminent demise of F# since its first version 20 years ago.

A lot of major C# features were first implemented in F#. I think of it as a place for Microsoft engineers/researchers to be more experimental with novel features that still need to target the CLR (the dotnet VM). Sometimes even requiring changes to the CLR itself. In that lens, it has had a very large indirect financial impact on the dotnet ecosystem.