It still isn't default on Windows because they separated it from Windows so they could ship new versions of PowerShell faster than new versions of Windows are shipped[1]. The renumbering to the major version 7 was intended to communicate compatibility (via loading 5.1 internally where necessary).
I don't know that it's certain it ever will be default on Windows, IIRC the last things I read were that it might become an optional package in Windows.
[1] Six-monthly, now moving to annually to align with new versions of .Net Core.
I don't know that it's certain it ever will be default on Windows, IIRC the last things I read were that it might become an optional package in Windows.
[1] Six-monthly, now moving to annually to align with new versions of .Net Core.