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.
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.