I am kinda surprised how much Windows likes its wchar's. Windows had support for multi-byte codepages since early days, and it has ways to indicate compatibility level for individual apps.
It seems the solution would be simple: once UTF-8 introduced (back in 1996!), add new "UTF-8" codepage, add new "SetDefaultCodepageToUnicode()" function, and tell everyone that wchar_t is legacy and should not be used anymore. They could probably do it in time for Windows XP!
Instead, UTF-8 codepage was only introduced in Windows 7 (but had incomplete support), and finally got the proper support in Windows 10. That's a lot of time Windows programmers were forced to use UCS-2.
It seems the solution would be simple: once UTF-8 introduced (back in 1996!), add new "UTF-8" codepage, add new "SetDefaultCodepageToUnicode()" function, and tell everyone that wchar_t is legacy and should not be used anymore. They could probably do it in time for Windows XP!
Instead, UTF-8 codepage was only introduced in Windows 7 (but had incomplete support), and finally got the proper support in Windows 10. That's a lot of time Windows programmers were forced to use UCS-2.