Yeah, so I just tried typing cmake at this point after installing on my MacOS system:
If you install on current MacOS (10.15.17) and run cmake, nothing happens because the installer doesn't add it to the path. Don't know if that's by design, but I think at least the solution could be documented. All that's required is to drop into the terminal and:
echo PATH="/Applications/CMake.app/Contents/bin":"$PATH" >> ~/.zshenv
I could flesh out the instructions completely if it's deemed helpful.