It can only use one core at a time, but that is not the worst thing: CMake is interpreted and stringly typed, so every number will have to be converted string -> number and usually back on every use.

I get that sometimes we like to build useless things because they are elegant, or beautiful, or "cool" in some sense of the word. But CMake is not cool in any sense of the word! I can barely use it to write build files, and that too I have gladly offloaded to AI. Sometimes when looking at CMake files in a large project, I become nostalgic about Makefiles, but then I think about what the rewrite would entail, and I resign myself to my fate.