That's great for super large builds, but the point of this is to deal with "I have one file I want to compile which is taking 30 seconds to compile, and I only have like three files to compile, so it would be awesome if I could use all of the cores on my laptop to do this compile and get it down to 10 seconds or something".
I write template heavy code. I’ve recently refactored template instantiation across many object files. It’s faster, but a lot of work. It’d be great if I didn’t have to.