> Qt should create a vanilla c++ package and tooling manager like Rusts cargo for dependencies and tools (and make semantic versioning mandatory). [...] Make the tool open source with vanilla c++ (aka non Qt projects), only so it can become the de facto standard.
Or just use one that is already working: https://build2.org (bonus point: also gets rid of CMake).
There are even "Qt classic" packages for both Qt5 and Qt6: