To add a little: the core features of the language are pretty well baked in at this point. Evan even said "If you like what you see now, that’s pretty much what Elm is going to be for a while."[0] The `eq` typeclass is I guess the missing feature[1] that stands out the most right now—in brief: don't allow equality check on functions, regexes, or JS objects at compile time.

[0] https://discourse.elm-lang.org/t/where-can-we-find-the-roadm... [1] https://package.elm-lang.org/packages/elm/core/latest/Basics...