https://learn.microsoft.com/en-us/cpp/porting/upgrade-your-c...
MinGW does not provide its own CRT. Historically, it used msvcrt.dll, which is the old and outdated CRT for VC++ 6.0 that was included in Windows a long time ago. These days it can also use uCRT, and that is indeed the new default:
https://github.com/mingw-w64/mingw-w64/blob/master/mingw-w64...