Julia seems like such a superior language compared to R. What would be required for it to supplant R for statistical work (or some subset of it)?
The majority of researchers don’t care about the language superiority. They’re concerned with different issues and software tends to suffer from “publish and forget” attitude. Convenience matters, and R ecosystem is quite good.
And here Julia is a complete Godsend, since it makes it a joy to implement things from the bottom up.
Sure, you also need a language that already has dataframe libraries, plotting, editor support et cetera, and Julia is lacking behind Python and R in these areas. But Julia's getting there, and at the end of the day, it's a relatively low number of packages that are must-haves.