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.