Haskell's promise is not only FP. That's part of it though, of course, to have an ecosystem, which encourages to continue in an FP style. Haskell's promise is also strong type safety and, as a distinguisher to many langauges, lazyness by default. Aside from that, its implementation is quite performant, if one needs to worry about such things.
I will take a 20min build process for dependencies (probably a few commands, which hopefully are documented in the project's readme and probably only once for most of the lifetime of a project on your personal machine) over a language, that is quickly up and running, but breaks any number of basic principles (for example looking at JS) and lets me shoot myself in the foot. Some languages and the lessons we take from learning them are worth some initial effort. Of course it is not great, that things are not as easy, as they maybe could be, but if the language has other perks making up for that, it might still be worthwhile.
