Microsoft has never taken it seriously, often releasing Visual Studio with broken F# support. It's fine for something you want to tinker with (like say Elm), but not something that's easy to sell to engineering managers when starting a new project.
Ionide and Rider are other options too. But I thought the broken F# support in VS is a thing of the past now?
Imho the bigger problem is that the C# language designer continue to not take F# into account. Structs and SUM types could be a shared MSIL story perhaps.
F# is absolutely alright. It has a small but nice community and various libraries that follow similar pattern - the selection may be small but the product is usually high quality.
It is a predominantly community-developed language. Microsoft contributes engineers to ensure that F# works, slowly evolves and is able to consume all the new APIs introduced in C#, while community drives the evolution of F#'s own features. You can write your own RFC, have it pass through the review, get signed off by Don Syme and then, once approved, implement it (or have it implemented by someone else). Each new release usually has multiple features driven by F# community this way.
Give it a try and if you have questions - feel free to ask them on F# discord.
