In addition, zig cc uses a remarkable compile+cache mechanism, which makes it possible to distribute a single build that can be used to cross-compile anything. It will cross-compile the necessary files as you need them, transparently - without downloading a new toolchain for each target, and quickly.

zig cc is really, really cool, and it's incredibly generous that it provides zig's benefits to users of C and C++ as well.

When you put it that way, this is an unfair comparison and the downsides are more obvious.

With GCC and Clang, I only pay for cross compilation if I need it, so for a fair comparison, the cross-compiler libraries should be installed for GCC and Clang. Also with GCC and Clang, I don't have to worry about a third party (the Zig team) incorporating bug and security fixes from upstream. And with GCC I get support for more platforms.

If I have chosen to use cross-compilation, building for alternative architectures is just as easy as for Zig.

Although as mentioned in the article, this won't work on systems like *BSD, Solaris or macOS.