This is only true because after a few years the front-end guys want and probably get to re-write their code for some new design or the latest fizz-bang framewor

This is only true because after a few years the front-end guys want and probably get to re-write their code for some new design or the latest fizz-bang framework. So they don't have to refactor / maintain 5+ year old code. I would look at Elm as if it compiles you will not get a runtime error but Elm devs probably are even more scarce then Scala devs.