Julia absolutely is a general purpose language and has been from the beginning. However, there are plenty of languages that are fine for building websites, whereas there are no other languages with the combination of speed and usability that Julia offers in technical computing. It's a lovely language for doing all kinds of work and I personally mostly use it for non-technical computing these days — specifically to implement package management client/server infrastructure, which is mostly web + file system wrangling.

Can you compile Julia programs to native binaries with a singe command ? Can Julia run on mobile and embedded devices ? A real general purpose programming language should do all of those.

Oh, hello, interesting to see you here :D Perhaps you ought to say that you're a co-creator of the language...

True, I'm obviously biased, but at least I can attest to the intention: Julia has always been intended for general purpose computing with the additional (and very challenging requirement) that it be a general purpose language that's also excellent at technical computing, which turns out to be a remarkably hard additional requirement.

I think its website makes it pretty clear that it's mostly targeting scientists...

https://julialang.org/, https://docs.julialang.org/en/v1/ (The first two words of the Introduction are literally "scientific computing".)