[MichaelGG]

I've hired people to work on .net apps (C#) as well as hiring devs with no F# experience and this is simply not my experience at all. I hired someone to do a spike of a project in Rust, ditto. And just this last week I met with one of my consultants that just started using F# the week prior. His F# code isn't quite idiomatic but he's written ~1000 lines of usable code. I've personally investigated and made bugfixes to a system written in a language/platform in which I had no experience.

Therefore I think it's quite fine to say it takes a few days to learn a bit of a language, enough to start contributing. Enough that it's not "job security" to pick something that provides a real benefit.