I don’t think so. wchar_t is designed before UTF-8 era.
Using wchar_t in right way on Unix is hard. It is based on locale. mbstowcs may be buggy on some systems.
I don’t want to learn about wchar_t. I don’t want to force young people to learn about wchar_t too.
For example, vim uses Py_SetPythonHome. See this code.
Strictly speaking, vim should use Py_DecodeLocale instead of mbstowcs here, if I understand the API correctly. But I’m not sure.
This is one example of how embedding Python correctly on Unix is difficult.
path is bytes in Unix. So char* based APIs is simple and easy to configure paths.