With the exception of CMake evolution (now days a defacto standard), package managers (as Conan or vcpkg) or the support for new C++ standards in major compilers (clang, gcc, Visual) ;)
It's good that the C++ world has effectively standardized on something, but CMake still has a steep learning curve. I hate its structure as a jumbled mess of independent commands.
It needs more guidance for making simple, typical projects easy to set up, at the very least more stuff that works like ExternalProject_Add (a big powerful command with all its options clearly documented on one page).