True, a project that consists just of a bunch of C files that you can drop into your project and that works with (almost) any build settings is just as good, or

True, a project that consists just of a bunch of C files that you can drop into your project and that works with (almost) any build settings is just as good, or even better than "header only" libraries IMO. But both approaches are preferable to complicated libraries that are hard to build and force the use of a certain build framework.