Interestingly .Net has very performant exception handling as well. Not sure if something changed internally with Core, but using exceptions in place of return error codes was incredibly common within the .Net ecosystem.
.NET has always had slow exception handling because it tied/ties in Windows’ Structured Exception Handling (SEH); that’s rather slow but provides e.g. detailed stack traces even for mixed-mode callstacks.
Having ported some decently large codebases from OCaml to F#, the heavy use of exceptions in OCaml (where exceptions are very lightweight by design) had to be changed to normal control flow with monads to achieve good performance in F# — specifically because of .NET’s slow exception handling.
