The main thing that holds me back from using F# more is that the tooling is simply not up to par. Things as basic as doing a rename refactoring automatically are not really supported, or popping out part of an expression into a temporary variable with a hotkey.

Depending on what you are used to, that might not be a huge problem, but the drop-off from the experience of working in C# or Java or even Python with modern tooling is stark.

I wish that there was an F# zealot or three working at JetBrains lobbying for better support in Resharper or Rider.