F# users generally avoid hierarchal type systems that plague TS/C# etc.

Don Syme has a great talk about this, but essentially things get out of hand very very quickly.

https://youtu.be/1AZA1zoP-II?t=2408

With Fable you are able to take the simplicity and conciseness of F# and jack into the entire JS ecosystem without falling into the type hierarchy nonsense.

Firstly you can share code with .net and JS side. Secondly, you can do proper functional programming with F#. Third I find type system typescript as cryptic.