The big missing FP features in ECMAScript are pattern matching and pipe operator.

I know there are proposals but neither seems to be making much progress.

I like FP but shoehorning it in with libraries is ugly compared to having native syntax.

https://github.com/tc39/proposal-pipeline-operator - Stage 2

https://github.com/tc39/proposal-pattern-matching - Stage 1

Hopefully we get both in the next couple of years.