CMake is getting there, https://www.kitware.com/import-cmake-c20-modules, and you can easily use them on Visual C++ 2022. All my hobby coding is done with modules nowadays.

The problem with clang is called Apple and Google, as they decided to focus on their own languages (Swift, Objective-C, Carbon, C++17 being good enough), the compiler vendors that profit from clang forks haven't cared that much to contribute to upstream.

Meanwhile VC++ and GCC are quite green on C++20 compliance, and GCC modules are almost there as well.