Yes, and when it was announced, it took 2 minutes and IIRC 2-4GB of ram to compile (I believe this was with the LLVM backend). I consider 2 minutes to self compile a language slow. I have personally written a compiler for a simpler language than zig using only lua to bootstrap it and it takes less than a second self compile and 10s of MB of memory. But again, this is possible because this language is much simpler yet in some, but not all, ways it is significantly more expressive than zig.

WRT to the other backends, I was aware of them which is why I said _even with a different backend_. I don't think they have a prayer of self compiling zig in under a second with the current language design with any backend but I'd be happy to be proved wrong.