One issue is that make will default to only using one job (i.e. one cpu), and you need to pass `-j NUMBER` to make it use more, while Ninja is parallel by default.
For my uses, I've not found `ninja` to be much faster than `make -j8` on an 8-core machine.
I'm surely also in that range. It took us years to write this project, but 57 C files is a small project. Others find themselves in the range where the build decision-making itself can take seconds, with tools other than ninja. Ninja is pared down for speed; having to declare keywords before I used them made me feel young again.
I had to write these build files over again, and I just couldn't stomach the idea of writing another makefile.
For my uses, I've not found `ninja` to be much faster than `make -j8` on an 8-core machine.
Not that the defaults don't matter, of course.