I was once a bit of a Julia performance expert, but moved toward c++ for hobby projects even while still using Julia professionally.

I wrote a blog post at the time with exactly that punchline (not explicitly stated, but just look at the code!): https://spmd.org/posts/multithreadedallocations/ The example was similar to a real production-critical hot path from work.

Maybe things changed since I left Julia, but that was December 2023, for years after this blog post.