You're not wrong, but even then forking a well established, well designed and not anti-pattern-ridden project with a massive library of build recipes for your own purposes is still better than maintaining some bespoke code used by two projects that forces developers to go mad, give up and quit.

My point was maybe not articulated well: it wouldn't have to be vcpkg. Could be Conan or something else, as long as it's not making you waste your free time and actually help producing reproducible builds and distributables on each platform supported (Linux, BSD, Mac, Windows).