I was excited about Julia too but it now seems to be a relatively niche HPC language. It's about saving CPU time more than user time.
My sniff test for a successor language to R is whether it can replicate the tidyverse API with 100% fidelity. The API is already optimal for tabular data analysis, especially the dplyr core. It can be thought of as a specification for other languages to implement.
There is a great deal about how R works that is negotiable. But if the language can't implement dplyr to spec, or somehow doesn't "want to", it's not the language for the audience served by the tidyverse.
Follow-up: I did a little legwork and found some Julia folks who were also inspired to implement tidyverse as faithfully as possible: https://github.com/TidierOrg
Here's how dplyr-style chains look in their system:
using TidierData
using RDatasets
movies = dataset("ggplot2", "movies");
@chain movies begin
@mutate(Budget = Budget / 1_000_000)
@filter(Budget >= mean(skipmissing(Budget)))
@select(Title, Budget)
@slice(1:5)
end
Not a character-for-character match to dplyr, but gets much closer than most other attempts!
I think many of us saw Julia as the successor to R. Unfortunately, the package ecosystem---one of R's strongest points---still has a long way to go.