I don't think this is really a feature. It's nice that you can write more performant code in Julia directly and don't need to wrap lower level languages, without question, but the lack of libraries or library features is not a good thing. It's always better to use a general purpose library that's been battle tested than to write your own numerical mathematics code (because bugs in numerical code can take a long time to get noticed)
For specialized scientific computing applications, which would normally be written in C/C++, I would absolutely look into using Julia instead (though not sure what the openmp/mpi support is like). But I would also recommend against rolling your own numerical software unless you need to
You are much less likely to reinvent the wheel if you can add your one critical niche feature / bugfix to an existing library. In python, learning C and C build systems and python's C API are gigantic barriers to doing that.
More importantly, if every fast data manipulation needs to be written in C, a few of them can be profitably shared, but you need more than a few of them. Pretty soon you wind up with a giant dumping ground of undiscoverable API bloat. See: pandas.
https://pandas.pydata.org/pandas-docs/stable/reference/serie...
Even though it's long, it undersells the problem, because many of these methods have nontrivial overload semantics that open up like a fractal when you look in turn at their docs. The link also undersells the problem because this junkheap is evidently so incomplete that people are frequently forced to rely on numpy to extend it.
APIs should make hard things easy, but API gloveboxes like this make easy things hard. Minimal API + Performant Glue >> We do everything for you + You can't ever touch your own data or your perf dies + Good luck reverse engineering these semantics if you've forgotten the context and need to port it.
I think the language is really solidly designed, and gives you ridiculously more power AND productivity than python for a whole range of workloads. There are of course issues, but even in the short time I've been following & using the language these are being rapidly addressed. In particular: generally less rich system of libraries (but some Julia libraries are state of the art across all languages, mainly due to easy metaprogramming and multiple dispatch) + generally slow compile times (but this is improving rapidly with caching etc). I would also note that you often don't really need as many "libraries" as you do in python or R, since you can typically just write down the code you want to write, rather than being forced to find a library that wraps a C/C++ implementation like in python/r.